int32 Info Record
flt64 Info Record
q2c Input Format
This manual is for GNU PSPP version 0.4.0, software for statistical analysis.
Copyright © 1997, 1998, 2004, 2005 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with the Front-Cover Texts being “A GNU Manual,” and with the Back-Cover Texts as in (a) below. A copy of the license is included in the section entitled “GNU Free Documentation License.”(a) The FSF's Back-Cover Text is: “You have freedom to copy and modify this GNU Manual, like GNU software. Copies published by the Free Software Foundation raise funds for GNU development.”
PSPP is a tool for statistical analysis of sampled data. It reads a syntax file and a data file, analyzes the data, and writes the results to a listing file or to standard output.
The language accepted by PSPP is similar to those accepted by SPSS statistical products. The details of PSPP's language are given later in this manual.
PSPP produces output in two forms: tables and charts. Both of these can be written in several formats; currently, ASCII, PostScript, and HTML are supported. In the future, more drivers, such as PCL and X Window System drivers, may be developed. For now, Ghostscript, available from the Free Software Foundation, may be used to convert PostScript chart output to other formats.
The current version of PSPP, 0.4.0, is woefully incomplete in terms of its statistical procedure support. PSPP is a work in progress. The author hopes to support fully support all features in the products that PSPP replaces, eventually. The author welcomes questions, comments, donations, and code submissions. See Submitting Bug Reports, for instructions on contacting the author.
PSPP is not in the public domain; it is copyrighted and there are restrictions on its distribution, but these restrictions are designed to permit everything that a good cooperating citizen would want to do. What is not allowed is to try to prevent others from further sharing any version of this program that they might get from you.
Specifically, we want to make sure that you have the right to give away copies of PSPP, that you receive source code or else can get it if you want it, that you can change these programs or use pieces of them in new free programs, and that you know you can do these things.
To make sure that everyone has such rights, we have to forbid you to deprive anyone else of these rights. For example, if you distribute copies of PSPP, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must tell them their rights.
Also, for our own protection, we must make certain that everyone finds out that there is no warranty for PSPP. If these programs are modified by someone else and passed on, we want their recipients to know that what they have is not what we distributed, so that any problems introduced by others will not reflect on our reputation.
The precise conditions of the licenses for PSPP are found in the General Public Licenses that accompany them. This manual specifically is covered by the GNU Free Documentation License (see GNU Free Documentation License).
pspp [ -B dir | --config-dir=dir ] [ -o device | --device=device ]
[ -d var[=value] | --define=var[=value] ] [-u var | --undef=var ]
[ -f file | --out-file=file ] [ -p | --pipe ] [ -I- | --no-include ]
[ -I dir | --include=dir ] [ -i | --interactive ]
[ -n | --edit | --dry-run | --just-print | --recon ]
[ -r | --no-statrc ] [ -h | --help ] [ -l | --list ]
[ -c command | --command command ] [ -s | --safer ]
[ --testing-mode ] [ -V | --version ] [ -v | --verbose ]
[ key=value ] file....
Syntax files and output device substitutions can be specified on PSPP's command line:
-i or
--interactive option is given (see Language control options).
+ file2=valueThere is one other way to specify a syntax file, if your operating system supports it. If you have a syntax file foobar.stat, put the notation
#! /usr/local/bin/pspp
at the top, and mark the file as executable with chmod +x
foobar.stat. (If PSPP is not installed in /usr/local/bin,
then insert its actual installation directory into the syntax file
instead.) Now you should be able to invoke the syntax file just by
typing its name. You can include any options on the command line as
usual. PSPP entirely ignores any lines beginning with #!.
Configuration options are used to change PSPP's configuration for the current run. The configuration options are:
-a {compatible|enhanced}--algorithm={compatible|enhanced}compatible, then PSPP will use the same algorithms
as used by some proprietary statistical analysis packages.
This is not recommended, as these algorithms are inferior and in some cases
compeletely broken.
The default setting is enhanced.
Certain commands have subcommands which allow you to override this setting on
a per command basis.
-B dir--config-dir=dir-o device--device=device-d var[=value]--define=var[=value]-u var--undef=varInput and output options affect how PSPP reads input and writes output. These are the input and output options:
-f file--out-file=file-p--pipe-f file and --file=file options.
-I---no-include-I dir--include=dir-c command--command=command--testing-modemake
check and similar scripts.
Language control options control how PSPP syntax files are parsed and interpreted. The available language control options are:
-i--interactiveIn addition, this forces syntax files to be interpreted in interactive
mode, rather than the default batch mode. See Tokenizing lines, for
information on the differences between batch mode and interactive mode
command interpretation.
-n--edit--dry-run--just-print--recon-r--no-statrc-s--saferInformational options cause information about PSPP to be written to the terminal. Here are the available options:
-h--help-l--list-x {compatible|enhanced}--syntax={compatible|enhanced}compatible, then PSPP will only accept command syntax that
is compatible with the proprietary program SPSS.
If you choose enhanced then additional syntax will be available.
The default is enhanced.
-V--version-v--verboseThis option can be given multiple times to set the verbosity level to that value. The default verbosity level is 0, in which no informational messages will be displayed.
Higher verbosity levels cause messages to be displayed when the corresponding events take place.
Each verbosity level also includes messages from lower verbosity levels.
Please note: PSPP is not even close to completion. Only a few statistical procedures are implemented. PSPP is a work in progress.
This chapter discusses elements common to many PSPP commands. Later chapters will describe individual commands in detail.
PSPP divides most syntax file lines into series of short chunks called tokens. Tokens are then grouped to form commands, each of which tells PSPP to take some action—read in data, write out data, perform a statistical procedure, etc. Each type of token is described below.
. _ $ # @
Identifiers may be any length, but only the first 64 bytes are
significant. Identifiers are not case-sensitive: foobar,
Foobar, FooBar, FOOBAR, and FoObaR are
different representations of the same identifier.
Some identifiers are reserved. Reserved identifiers may not be used in any context besides those explicitly described in this manual. The reserved identifiers are:
ALL AND BY EQ GE GT LE LT NE NOT OR TO WITH
Reserved identifiers are always used as keywords. Other identifiers
may be used both as keywords and as user-defined identifiers, such as
variable names.
-5 3.14159265359 1e100 -.707 8945.
Negative numbers are expressed with a - prefix. However, in situations where a literal - token is expected, what appears to be a negative number is treated as - followed by a positive number.
No white space is allowed within a number token, except for horizontal white space between - and the rest of the number.
The last example above, 8945. will be interpreted as two
tokens, 8945 and ., if it is the last token on a line.
See Forming commands of tokens.
Strings can be concatenated using +, so that "a" + 'b' + 'c' is equivalent to 'abc'. Concatenation is useful for splitting a single string across multiple source lines. The maximum length of a string, after concatenation, is 255 characters.
Strings may also be expressed as hexadecimal, octal, or binary character values by prefixing the initial quote character by X, O, or B or their lowercase equivalents. Each pair, triplet, or octet of characters, according to the radix, is transformed into a single character with the given value. If there is an incomplete group of characters, the missing final digits are assumed to be 0. These forms of strings are nonportable because numeric values are associated with different characters by different operating systems. Therefore, their use should be confined to syntax files that will not be widely distributed.
The character with value 00 is reserved for
internal use by PSPP. Its use in strings causes an error and
replacement by a space character.
, / = ( ) + - * / ** < <= <> > >= ~= & | .
Most of these appear within the syntax of commands, but the period (.) punctuator is used only at the end of a command. It is a punctuator only as the last character on a line (except white space). When it is the last non-space character on a line, a period is not treated as part of another token, even if it would otherwise be part of, e.g., an identifier or a floating-point number.
Actually, the character that ends a command can be changed with SET's ENDCMD subcommand (see SET), but we do not recommend doing so. Throughout the remainder of this manual we will assume that the default setting is in effect.
Most PSPP commands share a common structure. A command begins with a command name, such as FREQUENCIES, DATA LIST, or N OF CASES. The command name may be abbreviated to its first word, and each word in the command name may be abbreviated to its first three or more characters, where these abbreviations are unambiguous.
The command name may be followed by one or more subcommands. Each subcommand begins with a subcommand name, which may be abbreviated to its first three letters. Some subcommands accept a series of one or more specifications, which follow the subcommand name, optionally separated from it by an equals sign (=). Specifications may be separated from each other by commas or spaces. Each subcommand must be separated from the next (if any) by a forward slash (/).
There are multiple ways to mark the end of a command. The most common way is to end the last line of the command with a period (.) as described in the previous section (see Tokens). A blank line, or one that consists only of white space or comments, also ends a command by default, although you can use the NULLINE subcommand of SET to disable this feature (see SET).
In batch mode only, that is, when reading commands from a file instead of an interactive user, any line that contains a non-space character in the leftmost column begins a new command. Thus, each command consists of a flush-left line followed by any number of lines indented from the left margin. In this mode, a plus sign, minus sign, or period (+, −, or .) as the first character in a line is ignored and causes that line to begin a new command, which allows for visual indentation of a command without that command being considered part of the previous command.
Sometimes, one encounters syntax files that are intended to be interpreted in interactive mode rather than batch mode. When this occurs, use the -i command line option to force interpretation in interactive mode (see Language control options).
Commands in PSPP are divided roughly into six categories:
PSPP does not place many restrictions on ordering of commands. The main restriction is that variables must be defined before they are otherwise referenced. This section describes the details of command ordering, but most users will have no need to refer to them.
PSPP possesses five internal states, called initial, INPUT PROGRAM, FILE TYPE, transformation, and procedure states. (Please note the distinction between the INPUT PROGRAM and FILE TYPE commands and the INPUT PROGRAM and FILE TYPE states.)
PSPP starts in the initial state. Each successful completion of a command may cause a state transition. Each type of command has its own rules for state transitions:
PSPP includes special support for unknown numeric data values. Missing observations are assigned a special value, called the system-missing value. This “value” actually indicates the absence of a value; it means that the actual value is unknown. Procedures automatically exclude from analyses those observations or cases that have missing values. Details of missing value exclusion depend on the procedure and can often be controlled by the user; refer to descriptions of individual procedures for details.
The system-missing value exists only for numeric variables. String variables always have a defined value, even if it is only a string of spaces.
Variables, whether numeric or string, can have designated user-missing values. Every user-missing value is an actual value for that variable. However, most of the time user-missing values are treated in the same way as the system-missing value. String variables that are wider than a certain width, usually 8 characters (depending on computer architecture), cannot have user-missing values.
For more information on missing values, see the following sections: Variables, MISSING VALUES, Expressions. See also the documentation on individual procedures for information on how they handle missing values.
Variables are the basic unit of data storage in PSPP. All the variables in a file taken together, apart from any associated data, are said to form a dictionary. Some details of variables are described in the sections below.
Each variable has a number of attributes, including:
Some system variable names begin with $, but user-defined variables' names may not begin with $.
The final character in a variable name should not be ., because
such an identifier will be misinterpreted when it is the final token
on a line: FOO. will be divided into two separate tokens,
FOO and ., indicating end-of-command. See Tokens.
The final character in a variable name should not be _, because some such identifiers are used for special purposes by PSPP procedures.
As with all PSPP identifiers, variable names are not case-sensitive. PSPP capitalizes variable names on output the same way they were capitalized at their point of definition in the input.
Certain systems may consider strings longer than 8
characters to be short strings. Eight characters represents a minimum
figure for the maximum length of a short string.
There are seven system variables. These are not like ordinary variables because system variables are not always stored. They can be used only in expressions. These system variables, whose values and output formats cannot be modified, are described below.
$CASENUM$DATEDD MMM YY.
$JDATE$LENGTH$SYSMIS$TIME$WIDTH
To refer to a set of variables, list their names one after another.
Optionally, their names may be separated by commas. To include a
range of variables from the dictionary in the list, write the name of
the first and last variable in the range, separated by TO. For
instance, if the dictionary contains six variables with the names
ID, X1, X2, GOAL, MET, and
NEXTGOAL, in that order, then X2 TO MET would include
variables X2, GOAL, and MET.
Commands that define variables, such as DATA LIST, give
TO an alternate meaning. With these commands, TO define
sequences of variables whose names end in consecutive integers. The
syntax is two identifiers that begin with the same root and end with
numbers, separated by TO. The syntax X1 TO X5 defines 5
variables, named X1, X2, X3, X4, and
X5. The syntax ITEM0008 TO ITEM0013 defines 6
variables, named ITEM0008, ITEM0009, ITEM0010,
ITEM0011, ITEM0012, and ITEM00013. The syntaxes
QUES001 TO QUES9 and QUES6 TO QUES3 are invalid.
After a set of variables has been defined with DATA LIST or another command with this method, the same set can be referenced on later commands using the same syntax.
Data that PSPP inputs and outputs must have one of a number of formats.
These formats are described, in general, by a format specification of
the form NAMEw.d, where name is the
format name and w is a field width. d is the optional
desired number of decimal places, if appropriate. If d is not
included then it is assumed to be 0. Some formats do not allow d
to be specified.
When DATA LIST or another command specifies an input format, that format is converted to an output format for the purposes of PRINT and other data output commands. For most purposes, input and output formats are the same; the salient differences are described below.
Below are listed the input and output formats supported by PSPP. If an input format is mapped to a different output format by default, then that mapping is indicated with =>. Each format has the listed bounds on input width (iw) and output width (ow).
The standard numeric input and output formats are given in the following table:
1.2+34) if w >= 6, with always at least two digits in
the exponent. When used as an input format, scientific notation is
allowed but an E or an F must be used to introduce the exponent.
The default output format is the same as the input format, except if
d > 1. In that case the output w is always made to be at
least 2 + d.
1.2+34. There are always at least two
digits given in the exponent.
The default output w is the largest of the input w, the
input d + 7, and 10. The default output d is the input
d, but at least 3.
The default output w is the input w, but at least 2.
The default output w is the input w, but at least 2.
The default output format is F with the same w and d, except
if d > 1. In that case the output w is always made to be at
least 2 + d.
The default output format is F8.2 if d is 0. Otherwise it is F,
with output w as 9 + input d and output d as input
d.
The default output format follows the rules for IB format.
The default output format follows the rules for IB format.
The default output format follows the rules for IB format.
The default output format follows the rules for IB format.
The input width is mapped to a default output width as follows:
2=>4, 4=>6, 6=>9, 8=>11, 10=>14,
12=>16, 14=>18, 16=>21. No allowances are made for
decimal places.
The default output format is F8.2.
The date and time numeric input and output formats accept a number of possible formats. Before describing the formats themselves, some definitions of the elements that make up their formats will be helpful:
- / . ,
The date input formats are strung together from the above pieces. On output, the date formats are always printed in a single canonical manner, based on field width. The date input and output formats are described below:
Q Q
YYYY otherwise.
There are only two formats that may be used with string variables:
The default output w is half the input w.
Most of the time, variables don't retain their values between cases. Instead, either they're being read from a data file or the active file, in which case they assume the value read, or, if created with COMPUTE or another transformation, they're initialized to the system-missing value or to blanks, depending on type.
However, sometimes it's useful to have a variable that keeps its value between cases. You can do this with LEAVE (see LEAVE), or you can use a scratch variable. Scratch variables are variables whose names begin with an octothorpe (#).
Scratch variables have the same properties as variables left with LEAVE: they retain their values between cases, and for the first case they are initialized to 0 or blanks. They have the additional property that they are deleted before the execution of any procedure. For this reason, scratch variables can't be used for analysis. To use a scratch variable in an analysis, use COMPUTE (see COMPUTE) to copy its value into an ordinary variable, then use that ordinary variable in the analysis.
PSPP makes use of many files each time it runs. Some of these it reads, some it writes, some it creates. Here is a table listing the most important of these files:
The syntax of some parts of the PSPP language is presented in this manual using the formalism known as Backus-Naur Form, or BNF. The following table describes BNF:
numberintegerstringvar-name=, /, +, -, etc..var-listALL.
expressionExpressions share a common syntax each place they appear in PSPP commands. Expressions are made up of operands, which can be numbers, strings, or variable names, separated by operators. There are five types of operators: grouping, arithmetic, logical, relational, and functions.
Every operator takes one or more operands as input and yields exactly one result as output. Depending on the operator, operands accept strings or numbers as operands. With few exceptions, operands may be full-fledged expressions in themselves.
Some PSPP operators and expressions work with Boolean values, which represent true/false conditions. Booleans have only three possible values: 0 (false), 1 (true), and system-missing (unknown). System-missing is neither true nor false and indicates that the true value is unknown.
Boolean-typed operands or function arguments must take on one of these three values. Other values are considered false, but provoke a warning when the expression is evaluated.
Strings and Booleans are not compatible, and neither may be used in place of the other.
Most numeric operators yield system-missing when given any system-missing operand. A string operator given any system-missing operand typically results in the empty string. Exceptions are listed under particular operator descriptions.
String user-missing values are not treated specially in expressions.
User-missing values for numeric variables are always transformed into
the system-missing value, except inside the arguments to the
VALUE and SYSMIS functions.
The missing-value functions can be used to precisely control how missing values are treated in expressions. See Missing Value Functions, for more details.
Parentheses (()) are the grouping operators. Surround an expression with parentheses to force early evaluation.
Parentheses also surround the arguments to functions, but in that situation they act as punctuators, not as operators.
The arithmetic operators take numeric operands and produce numeric results.
+ b - b * b / b ** b0**0 is system-missing as well.
- aThe logical operators take logical operands and produce logical results, meaning “true or false.” Logical operators are not true Boolean operators because they may also result in a system-missing value. See Boolean Values, for more information.
AND b & b OR b | bNOT a~ aThe relational operators take numeric or string operands and produce Boolean results.
Strings cannot be compared to numbers. When strings of different lengths are compared, the shorter string is right-padded with spaces to match the length of the longer string.
The results of string comparisons, other than tests for equality or inequality, depend on the character set in use. String comparisons are case-sensitive.
EQ b = b LE b <= b LT b < b GE b >= b GT b > b NE b ~= b <> bPSPP functions provide mathematical abilities above and beyond those possible using simple operators. Functions have a common syntax: each is composed of a function name followed by a left parenthesis, one or more arguments, and a right parenthesis.
Function names are not reserved. Their names are specially treated
only when followed by a left parenthesis, so that EXP(10)
refers to the constant value e raised to the 10th power, but
EXP by itself refers to the value of variable EXP.
The sections below describe each function in detail.
Advanced mathematical functions take numeric arguments and produce numeric results.
Takes the base-10 logarithm of number. If number is not positive, the result is system-missing.
Takes the base-e logarithm of number. If number is not positive, the result is system-missing.
Yields the base-e logarithm of the complete gamma of number. If number is a negative integer, the result is system-missing.
Takes the square root of number. If number is negative, the result is system-missing.
Miscellaneous mathematical functions take numeric arguments and produce numeric results.
Returns the remainder (modulus) of numerator divided by denominator. If numerator is 0, then the result is 0, even if denominator is missing. If denominator is 0, the result is system-missing.
Returns the remainder when number is divided by 10. If number is negative, MOD10(number) is negative or zero.
Takes the absolute value of number and rounds it to an integer. Then, if number was negative originally, negates the result.
Discards the fractional part of number; that is, rounds number towards zero.
Trigonometric functions take numeric arguments and produce numeric results.
Takes the arccosine, in radians, of number. Results in system-missing if number is not between -1 and 1 inclusive. This function is a PSPP extension.
Takes the arcsine, in radians, of number. Results in system-missing if number is not between -1 and 1 inclusive.
Takes the tangent of angle which should be in radians. Results in system-missing at values of angle that are too close to odd multiples of pi/2. Portability: none.
Missing-value functions take various numeric arguments and yield various types of results. Except where otherwise stated below, the normal rules of evaluation apply within expression arguments to these functions. In particular, user-missing values for numeric variables are converted to system-missing values.
Each argument must be a numeric expression. Returns the number of system-missing values in the list, which may include variable ranges using the var1
TOvar2 syntax.
Each argument must be a numeric expression. Returns the number of values in the list that are not system-missing. The list may include variable ranges using the var1
TOvar2 syntax.
When expr is simply the name of a numeric variable, returns 1 if the variable has the system-missing value, 0 if it is user-missing or not missing. If given expr takes another form, results in 1 if the value is system-missing, 0 otherwise.
Prevents the user-missing values of variable from being transformed into system-missing values, and always results in the actual value of variable, whether it is valid, user-missing, or system-missing.
Set membership functions determine whether a value is a member of a set. They take a set of numeric arguments or a set of string arguments, and produce Boolean results.
String comparisons are performed according to the rules given in Relational Operators.
Results in true if value is equal to any of the set values. Otherwise, results in false. If value is system-missing, returns system-missing. System-missing values in set do not cause ANY to return system-missing.
Results in true if value is in any of the intervals bounded by low and high inclusive. Otherwise, results in false. Each low must be less than or equal to its corresponding high value. low and high must be given in pairs. If value is system-missing, returns system-missing. System-missing values in set do not cause RANGE to return system-missing.
Statistical functions compute descriptive statistics on a list of values. Some statistics can be computed on numeric or string values; other can only be computed on numeric values. Their results have the same type as their arguments. The current case's weighting factor (see WEIGHT) has no effect on statistical functions.
These functions' argument lists may include entire ranges of variables
using the var1 TO var2 syntax.
Unlike most functions, statistical functions can return non-missing
values even when some of their arguments are missing. Most
statistical functions, by default, require only 1 non-missing value to
have a non-missing return, but CFVAR, SD, and VARIANCE require 2.
These defaults can be increased (but not decreased) by appending a dot
and the minimum number of valid arguments to the function name. For
example, MEAN.3(X, Y, Z) would only return non-missing if all
of X, Y, and Z were valid.
Results in the coefficient of variation of the values of number. (The coefficient of variation is the standard deviation divided by the mean.)
Results in the value of the greatest value. The values may be numeric or string.
Results in the value of the least value. The values may be numeric or string.
String functions take various arguments and return various results.
Returns a string consisting of each string in sequence.
CONCAT("abc", "def", "ghi")has a value of"abcdefghi". The resultant string is truncated to a maximum of 255 characters.
Returns a positive integer indicating the position of the first occurrence of needle in haystack. Returns 0 if haystack does not contain needle. Returns system-missing if needle is an empty string.
Divides needles into one or more needles, each with length needle_len. Searches haystack for the first occurrence of each needle, and returns the smallest value. Returns 0 if haystack does not contain any part in needle. It is an error if needle_len does not evenly divide the length of needles. Returns system-missing if needles is an empty string.
Returns a string identical to string except that all uppercase letters are changed to lowercase letters. The definitions of “uppercase” and “lowercase” are system-dependent.
If string is at least length characters in length, returns string unchanged. Otherwise, returns string padded with spaces on the left side to length length. Returns an empty string if length is system-missing, negative, or greater than 255.
If string is at least length characters in length, returns string unchanged. Otherwise, returns string padded with padding on the left side to length length. Returns an empty string if length is system-missing, negative, or greater than 255, or if padding does not contain exactly one character.
Returns string, after removing leading spaces. Other white space, such as tabs, carriage returns, line feeds, and vertical tabs, is not removed.
Returns string, after removing leading padding characters. If padding does not contain exactly one character, returns an empty string.
Returns the number produced when string is interpreted according to format specifier format. If the format width w is less than the length of string, then only the first w characters in string are used, e.g.
NUMBER("123", F3.0)andNUMBER("1234", F3.0)both have value 123. If w is greater than string's length, then it is treated as if it were right-padded with spaces. If string is not in the correct format for format, system-missing is returned.
Returns a positive integer indicating the position of the last occurrence of needle in haystack. Returns 0 if haystack does not contain needle. Returns system-missing if needle is an empty string.
Divides needle into parts, each with length needle_len. Searches haystack for the last occurrence of each part, and returns the largest value. Returns 0 if haystack does not contain any part in needle. It is an error if needle_len does not evenly divide the length of needle. Returns system-missing if needle is an empty string.
If string is at least length characters in length, returns string unchanged. Otherwise, returns string padded with spaces on the right to length length. Returns an empty string if length is system-missing, negative, or greater than 255.
If string is at least length characters in length, returns string unchanged. Otherwise, returns string padded with padding on the right to length length. Returns an empty string if length is system-missing, negative, or greater than 255, or if padding does not contain exactly one character.
Returns string, after removing trailing spaces. Other types of white space are not removed.
Returns string, after removing trailing padding characters. If padding does not contain exactly one character, returns an empty string.
Returns a string corresponding to number in the format given by format specifier format. For example,
STRING(123.56, F5.1)has the value"123.6".
Returns a string consisting of the value of string from position start onward. Returns an empty string if start is system-missing, less than 1, or greater than the length of string.
Returns a string consisting of the first count characters from string beginning at position start. Returns an empty string if start or count is system-missing, if start is less than 1 or greater than the number of characters in string, or if count is less than 1. Returns a string shorter than count characters if start + count - 1 is greater than the number of characters in string. Examples:
SUBSTR("abcdefg", 3, 2)has value"cd";SUBSTR("nonsense", 4, 10)has the value"sense".
For compatibility, PSPP considers dates before 15 Oct 1582 invalid. Most time and date functions will not accept earlier dates.
Times and dates are handled by PSPP as single numbers. A time is an interval. PSPP measures times in seconds. Thus, the following intervals correspond with the numeric values given:
10 minutes 600
1 hour 3,600
1 day, 3 hours, 10 seconds 97,210
40 days 3,456,000
A date, on the other hand, is a particular instant in the past or the future. PSPP represents a date as a number of seconds since midnight preceding 14 Oct 1582. Because midnight preceding the dates given below correspond with the numeric PSPP dates given:
15 Oct 1582 86,400
4 Jul 1776 6,113,318,400
1 Jan 1900 10,010,390,400
1 Oct 1978 12,495,427,200
24 Aug 1995 13,028,601,600
Ordinary arithmetic operations on dates and times often produce sensible results. Adding a time to, or subtracting one from, a date produces a new date that much earlier or later. The difference of two dates yields the time between those dates. Adding two times produces the combined time. Multiplying a time by a scalar produces a time that many times longer. Since times and dates are just numbers, the ordinary addition and subtraction operators are employed for these purposes.
Adding two dates does not produce a useful result.
As the table shows, dates and times may have very large values. Thus, it is not a good idea to take powers of these values; also, the accuracy of some procedures may be affected. If necessary, convert times or dates in seconds to some other unit, like days or years, before performing analysis.
These functions take numeric arguments and return numeric values that represent times.
Returns a time corresponding to nhours hours, nmins minutes, and nsecs seconds. The arguments may not have mixed signs: if any of them are positive, then none may be negative, and vice versa.
These functions take numeric arguments in PSPP time format and give numeric results.
Results in the number of seconds and fractional seconds in time. (
CTIME.SECONDSdoes nothing;CTIME.SECONDS(x)is equivalent to x.)
These functions take numeric arguments and give numeric results that represent dates. Arguments taken by these functions are:
If these functions' arguments are out-of-range, they are correctly normalized before conversion to date format. Non-integers are rounded toward zero.
Results in a date value corresponding to the midnight before day day of month month of year year.
Results in a date value corresponding to the midnight before the first day of month month of year year.
Results in a date value corresponding to the midnight before the first day of quarter quarter of year year.
Results in a date value corresponding to the midnight before the first day of week week of year year.
Results in a date value corresponding to the day yday of year year.
These functions take numeric arguments in PSPP date or time format and give numeric results. These names are used for arguments:
For a time, results in the time corresponding to the number of whole days date-or-time includes. For a date, results in the date corresponding to the latest midnight at or before date-or-time; that is, gives the date that date-or-time is in.
For a time, results in the number of whole hours beyond the number of whole days represented by date-or-time. For a date, results in the hour (as an integer between 0 and 23) corresponding to date-or-time.
Results in the day of the year (as an integer between 1 and 366) corresponding to date.
Results in the day of the month (as an integer between 1 and 31) corresponding to date.
Results in the number of minutes (as an integer between 0 and 59) after the last hour in time-or-date.
Results in the month of the year (as an integer between 1 and 12) corresponding to date.
Results in the quarter of the year (as an integer between 1 and 4) corresponding to date.
Results in the number of whole seconds after the last whole minute (as an integer between 0 and 59) in time-or-date.
Results in the time of day at the instant corresponding to date, as a time value. This is the number of seconds since midnight on the day corresponding to date.
Results in the week of the year (as an integer between 1 and 53) corresponding to date.
Results in the day of week (as an integer between 1 and 7) corresponding to date, where 1 represents Sunday.
Returns the year (as an integer 1582 or greater) corresponding to date.
Miscellaneous functions take various arguments and produce various results.
variable must be a numeric or string variable name.
LAGresults in the value of that variable for the case ncases before the current one. In case-selection procedures,LAGresults in the value of the variable for the last case selected. Results in system-missing (for numeric variables) or blanks (for string variables) for the first case or before any cases are selected.If omitted, ncases defaults to 1. Otherwise, ncases must be a small positive constant integer. There is no explicit limit, but use of a large value will increase memory consumption.
year is a year, either between 0 and 99 or at least 1582. Unlike other PSPP date functions, years between 0 and 99 always correspond to 1900 through 1999. month is a month between 1 and 13. day is a day between 0 and 31. A day of 0 refers to the last day of the previous month, and a month of 13 refers to the first month of the next year. year must be in range. year, month, and day must all be integers.
YRMODAresults in the number of days between 15 Oct 1582 and the date specified, plus one. The date passed toYRMODAmust be on or after 15 Oct 1582. 15 Oct 1582 has a value of 1.
PSPP can calculate several functions of standard statistical distributions. These functions are named systematically based on the function and the distribution. The table below describes the statistical distribution functions in general:
The individual distributions are described individually below.
The following continuous distributions are available:
Beta distribution with shape parameters a and b. The noncentral distribution takes an additional parameter lambda. Constraints: a > 0, b > 0, lambda >= 0, 0 <= x <= 1, 0 <= p <= 1.
Bivariate normal distribution of two standard normal variables with correlation coefficient rho. Two variates x0 and x1 must be provided. Constraints: 0 <= rho <= 1, 0 <= p <= 1.
Cauchy distribution with location parameter a and scale parameter b. Constraints: b > 0, 0 < p < 1.
Chi-squared distribution with df degrees of freedom. The noncentral distribution takes an additional parameter lambda. Constraints: df > 0, lambda > 0, x >= 0, 0 <= p < 1.
Exponential distribution with scale parameter a. The inverse of a represents the rate of decay. Constraints: a > 0, x >= 0, 0 <= p < 1.
Exponential power distribution with positive scale parameter a and nonnegative power parameter b. Constraints: a > 0, b >= 0, x >= 0, 0 <= p <= 1. This distribution is a PSPP extension.
F-distribution of two chi-squared deviates with df1 and df2 degrees of freedom. The noncentral distribution takes an additional parameter lambda. Constraints: df1 > 0, df2 > 0, lambda >= 0, x >= 0, 0 <= p < 1.
Gamma distribution with shape parameter a and scale parameter b. Constraints: a > 0, b > 0, x >= 0, 0 <= p < 1.
Half-normal distribution with location parameter a and shape parameter b. Constraints: b > 0, 0 < p < 1.
Inverse Gaussian distribution with parameters a and b. Constraints: a > 0, b > 0, x > 0, 0 <= p < 1.
Laplace distribution with location parameter a and scale parameter b. Constraints: b > 0, 0 < p < 1.
Levy symmetric alpha-stable distribution with scale c and exponent alpha. Constraints: 0 < alpha <= 2.
Levy skew alpha-stable distribution with scale c, exponent alpha, and skewness parameter beta. Constraints: 0 < alpha <= 2, -1 <= beta <= 1.
Logistic distribution with location parameter a and scale parameter b. Constraints: b > 0, 0 < p < 1.
Lognormal distribution with parameters a and b. Constraints: a > 0, b > 0, x >= 0, 0 <= p < 1.
Normal distribution with mean mu and standard deviation sigma. Constraints: b > 0, 0 < p < 1. Three additional functions are available as shorthand:
Normal tail distribution with lower limit a and standard deviation sigma. This distribution is a PSPP extension. Constraints: a > 0, x > a, 0 < p < 1.
Pareto distribution with threshold parameter a and shape parameter b. Constraints: a > 0, b > 0, x >= a, 0 <= p < 1.
Rayleigh distribution with scale parameter sigma. This distribution is a PSPP extension. Constraints: sigma > 0, x > 0.
Rayleigh tail distribution with lower limit a and scale parameter sigma. This distribution is a PSPP extension. Constraints: a > 0, sigma > 0, x > a.
Studentized maximum modulus distribution with parameters a and b. Constraints: a > 0, b > 0, x > 0, 0 <= p < 1.
Studentized range distribution with parameters a and b. Constraints: a >= 1, b >= 1, x > 0, 0 <= p < 1.
T-distribution with df degrees of freedom. The noncentral distribution takes an additional parameter lambda. Constraints: df > 0, 0 < p < 1.
Type-1 Gumbel distribution with parameters a and b. This distribution is a PSPP extension. Constraints: 0 < p < 1.
Type-2 Gumbel distribution with parameters a and b. This distribution is a PSPP extension. Constraints: x > 0, 0 < p < 1.
Uniform distribution with parameters a and b. Constraints: a <= x <= b, 0 <= p <= 1. An additional function is available as shorthand:
Weibull distribution with parameters a and b. Constraints: a > 0, b > 0, x >= 0, 0 <= p < 1.
The following discrete distributions are available:
Bernoulli distribution with probability of success p. Constraints: x = 0 or 1, 0 <= p <= 1.
Binomial distribution with n trials and probability of success p. Constraints: integer n > 0, 0 <= p <= 1, integer x <= n.
Geometric distribution with probability of success p. Constraints: 0 <= p <= 1, integer x > 0.
Hypergeometric distribution when b objects out of a are drawn and c of the available objects are distinctive. Constraints: integer a > 0, integer b <= a, integer c <= a, integer x >= 0.
Logarithmic distribution with probability parameter p. Constraints: 0 <= p < 1, x >= 1.
Negative binomial distribution with number of successes paramter n and probability of success parameter p. Constraints: integer n >= 0, 0 < p <= 1, integer x >= 1.
Poisson distribution with mean mu. Constraints: mu > 0, integer x >= 0.
The following table describes operator precedence. Smaller-numbered levels in the table have higher precedence. Within a level, operations are always performed from left to right. The first occurrence of - represents unary negation, the second binary subtraction.
( )
**
-
* /
+ -
EQ GE GT LE LT NE
AND NOT OR
Data are the focus of the PSPP language. Each datum belongs to a case (also called an observation). Each case represents an individual or `experimental unit'. For example, in the results of a survey, the names of the respondents, their sex, age etc. and their responses are all data and the data pertaining to single respondent is a case. This chapter examines the PSPP commands for defining variables and reading and writing data.
Please note: Data is not actually read until a procedure is executed. These commands tell PSPP how to read data, but they do not cause PSPP to read data.
BEGIN DATA.
...
END DATA.
BEGIN DATA and END DATA can be used to embed raw ASCII
data in a PSPP syntax file. DATA LIST or another input
procedure must be used before BEGIN DATA (see DATA LIST).
BEGIN DATA and END DATA must be used together. END
DATA must appear by itself on a single line, with no leading
white space and exactly one space between the words END and
DATA, like this:
END DATA.
CLEAR TRANSFORMATIONS.
CLEAR TRANSFORMATIONS clears out all pending transformations. It does not cancel the current input program. It is valid only when PSPP is interactive, not in syntax files.
Used to read text or binary data, DATA LIST is the most fundamental data-reading command. Even the more sophisticated input methods use DATA LIST commands as a building block. Understanding DATA LIST is important to understanding how to use PSPP to read your data files.
There are two major variants of DATA LIST, which are fixed format and free format. In addition, free format has a minor variant, list format, which is discussed in terms of its differences from vanilla free format.
Each form of DATA LIST is described in detail below.
DATA LIST [FIXED]
{TABLE,NOTABLE}
FILE='filename'
RECORDS=record_count
END=end_var
/[line_no] var_spec...
where each var_spec takes one of the forms
var_list start-end [type_spec]
var_list (fortran_spec)
DATA LIST FIXED is used to read data files that have values at fixed positions on each line of single-line or multiline records. The keyword FIXED is optional.
The FILE subcommand must be used if input is to be taken from an external file. It may be used to specify a filename as a string or a file handle (see FILE HANDLE). If the FILE subcommand is not used, then input is assumed to be specified within the command file using BEGIN DATA...END DATA (see BEGIN DATA).
The optional RECORDS subcommand, which takes a single integer as an argument, is used to specify the number of lines per record. If RECORDS is not specified, then the number of lines per record is calculated from the list of variable specifications later in DATA LIST.
The END subcommand is only useful in conjunction with INPUT PROGRAM. See INPUT PROGRAM, for details.
DATA LIST can optionally output a table describing how the data file will be read. The TABLE subcommand enables this output, and NOTABLE disables it. The default is to output the table.
The list of variables to be read from the data list must come last. Each line in the data record is introduced by a slash (/). Optionally, a line number may follow the slash. Following, any number of variable specifications may be present.
Each variable specification consists of a list of variable names
followed by a description of their location on the input line. Sets of
variables may specified using the DATA LIST TO convention
(see Sets of Variables). There are two ways to specify the location of the variable
on the line: columnar style and FORTRAN style.
In columnar style, the starting column and ending column for the field are specified after the variable name, separated by a dash (-). For instance, the third through fifth columns on a line would be specified 3-5. By default, variables are considered to be in F format (see Input/Output Formats). (This default can be changed; see SET for more information.)
In columnar style, to use a variable format other than the default, specify the format type in parentheses after the column numbers. For instance, for alphanumeric A format, use (A).
In addition, implied decimal places can be specified in parentheses after the column numbers. As an example, suppose that a data file has a field in which the characters 1234 should be interpreted as having the value 12.34. Then this field has two implied decimal places, and the corresponding specification would be (2). If a field that has implied decimal places contains a decimal point, then the implied decimal places are not applied.
Changing the variable format and adding implied decimal places can be done together; for instance, (N,5).
When using columnar style, the input and output width of each variable is computed from the field width. The field width must be evenly divisible into the number of variables specified.
FORTRAN style is an altogether different approach to specifying field locations. With this approach, a list of variable input format specifications, separated by commas, are placed after the variable names inside parentheses. Each format specifier advances as many characters into the input line as it uses.
Implied decimal places also exist in FORTRAN style. A format specification with d decimal places also has d implied decimal places.
In addition to the standard format specifiers (see Input/Output Formats), FORTRAN style defines some extensions:
XTxNEWRECxFORTRAN and columnar styles may be freely intermixed. Columnar style
leaves the active column immediately after the ending column
specified. Record motion using NEWREC in FORTRAN style also
applies to later FORTRAN and columnar specifiers.
DATA LIST TABLE /NAME 1-10 (A) INFO1 TO INFO3 12-17 (1).
BEGIN DATA.
John Smith 102311
Bob Arnold 122015
Bill Yates 918 6
END DATA.
Defines the following variables:
NAME, a 10-character-wide long string variable, in columns 1
through 10.
INFO1, a numeric variable, in columns 12 through 13.
INFO2, a numeric variable, in columns 14 through 15.
INFO3, a numeric variable, in columns 16 through 17.
The BEGIN DATA/END DATA commands cause three cases to be
defined:
Case NAME INFO1 INFO2 INFO3
1 John Smith 10 23 11
2 Bob Arnold 12 20 15
3 Bill Yates 9 18 6
The TABLE keyword causes PSPP to print out a table
describing the four variables defined.
DAT LIS FIL="survey.dat"
/ID 1-5 NAME 7-36 (A) SURNAME 38-67 (A) MINITIAL 69 (A)
/Q01 TO Q50 7-56
/.
Defines the following variables:
ID, a numeric variable, in columns 1-5 of the first record.
NAME, a 30-character long string variable, in columns 7-36 of the
first record.
SURNAME, a 30-character long string variable, in columns 38-67 of
the first record.
MINITIAL, a 1-character short string variable, in column 69 of
the first record.
Q01, Q02, Q03, ..., Q49,
Q50, all numeric, Q01 in column 7, Q02 in column 8,
..., Q49 in column 55, Q50 in column 56, all in the second
record.
Cases are separated by a blank record.
Data is read from file survey.dat in the current directory.
This example shows keywords abbreviated to their first 3 letters.
DATA LIST FREE
[({TAB,'c'}, ...)]
[{NOTABLE,TABLE}]
FILE='filename'
END=end_var
/var_spec...
where each var_spec takes one of the forms
var_list [(type_spec)]
var_list *
In free format, the input data is, by default, structured as a series of fields separated by spaces, tabs, commas, or line breaks. Each field's content may be unquoted, or it may be quoted with a pairs of apostrophes (') or double quotes ("). Unquoted white space separates fields but is not part of any field. Any mix of spaces, tabs, and line breaks is equivalent to a single space for the purpose of separating fields, but consecutive commas will skip a field.
Alternatively, delimiters can be specified explicitly, as a parenthesized, comma-separated list of single-character strings immediately following FREE. The word TAB may also be used to specify a tab character as a delimiter. When delimiters are specified explicitly, only the given characters, plus line breaks, separate fields. Furthermore, leading spaces at the beginnings of fields are not trimmed, consecutive delimiters define empty fields, and no form of quoting is allowed.
The NOTABLE and TABLE subcommands are as in DATA LIST FIXED above. NOTABLE is the default.
The FILE and END subcommands are as in DATA LIST FIXED above.
The variables to be parsed are given as a single list of variable names. This list must be introduced by a single slash (/). The set of variable names may contain format specifications in parentheses (see Input/Output Formats). Format specifications apply to all variables back to the previous parenthesized format specification.
In addition, an asterisk may be used to indicate that all variables preceding it are to have input/output format F8.0.
Specified field widths are ignored on input, although all normal limits on field width apply, but they are honored on output.
DATA LIST LIST
[({TAB,'c'}, ...)]
[{NOTABLE,TABLE}]
FILE='filename'
END=end_var
/var_spec...
where each var_spec takes one of the forms
var_list [(type_spec)]
var_list *
With one exception, DATA LIST LIST is syntactically and semantically equivalent to DATA LIST FREE. The exception is that each input line is expected to correspond to exactly one input record. If more or fewer fields are found on an input line than expected, an appropriate diagnostic is issued.
END CASE.
END CASE is used only within INPUT PROGRAM to output the current case. See INPUT PROGRAM, for details.
END FILE.
END FILE is used only within INPUT PROGRAM to terminate the current input program. See INPUT PROGRAM.
FILE HANDLE handle_name
/NAME='filename'
/MODE={CHARACTER,IMAGE}
/LRECL=rec_len
/TABWIDTH=tab_width
Use FILE HANDLE to associate a file handle name with a file and its attributes, so that later commands can refer to the file by its handle name. Because names of text files can be specified directly on commands that access files, FILE HANDLE is only needed when a file is not an ordinary file containing lines of text. However, FILE HANDLE may be used even for text files, and it may be easier to specify a file's name once and later refer to it by an abstract handle.
Specify the file handle name as an identifier. Any given identifier may only appear once in a PSPP run. File handles may not be reassigned to a different file. The file handle name must immediately follow the FILE HANDLE command name.
The NAME subcommand specifies the name of the file associated with the handle. It is the only required subcommand.
MODE specifies a file mode. In CHARACTER mode, the default, the data file is opened in ANSI C text mode, so that local end of line conventions are followed, and each text line is read as one record. In CHARACTER mode, most input programs will expand tabs to spaces (DATA LIST FREE with explicitly specified delimiters is an exception). By default, each tab is 4 characters wide, but an alternate width may be specified on TABWIDTH. A tab width of 0 suppresses tab expansion entirely.
By contrast, in BINARY mode, the data file is opened in ANSI C binary mode and records are a fixed length. In BINARY mode, LRECL specifies the record length in bytes, with a default of 1024. Tab characters are never expanded to spaces in binary mode.
INPUT PROGRAM.
... input commands ...
END INPUT PROGRAM.
INPUT PROGRAM...END INPUT PROGRAM specifies a complex input program. By placing data input commands within INPUT PROGRAM, PSPP programs can take advantage of more complex file structures than available with only DATA LIST.
The first sort of extended input program is to simply put multiple DATA LIST commands within the INPUT PROGRAM. This will cause all of the data files to be read in parallel. Input will stop when end of file is reached on any of the data files.
Transformations, such as conditional and looping constructs, can also be included within INPUT PROGRAM. These can be used to combine input from several data files in more complex ways. However, input will still stop when end of file is reached on any of the data files.
To prevent INPUT PROGRAM from terminating at the first end of file, use the END subcommand on DATA LIST. This subcommand takes a variable name, which should be a numeric scratch variable (see Scratch Variables). (It need not be a scratch variable but otherwise the results can be surprising.) The value of this variable is set to 0 when reading the data file, or 1 when end of file is encountered.
Two additional commands are useful in conjunction with INPUT PROGRAM. END CASE is the first. Normally each loop through the INPUT PROGRAM structure produces one case. END CASE controls exactly when cases are output. When END CASE is used, looping from the end of INPUT PROGRAM to the beginning does not cause a case to be output.
END FILE is the second. When the END subcommand is used on DATA LIST, there is no way for the INPUT PROGRAM construct to stop looping, so an infinite loop results. END FILE, when executed, stops the flow of input data and passes out of the INPUT PROGRAM structure.
All this is very confusing. A few examples should help to clarify.
INPUT PROGRAM.
DATA LIST NOTABLE FILE='a.data'/X 1-10.
DATA LIST NOTABLE FILE='b.data'/Y 1-10.
END INPUT PROGRAM.
LIST.
The example above reads variable X from file a.data and variable Y from file b.data. If one file is shorter than the other then the extra data in the longer file is ignored.
INPUT PROGRAM.
NUMERIC #A #B.
DO IF NOT #A.
DATA LIST NOTABLE END=#A FILE='a.data'/X 1-10.
END IF.
DO IF NOT #B.
DATA LIST NOTABLE END=#B FILE='b.data'/Y 1-10.
END IF.
DO IF #A AND #B.
END FILE.
END IF.
END CASE.
END INPUT PROGRAM.
LIST.
The above example reads variable X from a.data and variable Y from b.data. If one file is shorter than the other then the missing field is set to the system-missing value alongside the present value for the remaining length of the longer file.
INPUT PROGRAM.
NUMERIC #A #B.
DO IF #A.
DATA LIST NOTABLE END=#B FILE='b.data'/X 1-10.
DO IF #B.
END FILE.
ELSE.
END CASE.
END IF.
ELSE.
DATA LIST NOTABLE END=#A FILE='a.data'/X 1-10.
DO IF NOT #A.
END CASE.
END IF.
END IF.
END INPUT PROGRAM.
LIST.
The above example reads data from file a.data, then from b.data, and concatenates them into a single active file.
INPUT PROGRAM.
NUMERIC #EOF.
LOOP IF NOT #EOF.
DATA LIST NOTABLE END=#EOF FILE='a.data'/X 1-10.
DO IF NOT #EOF.
END CASE.
END IF.
END LOOP.
COMPUTE #EOF = 0.
LOOP IF NOT #EOF.
DATA LIST NOTABLE END=#EOF FILE='b.data'/X 1-10.
DO IF NOT #EOF.
END CASE.
END IF.
END LOOP.
END FILE.
END INPUT PROGRAM.
LIST.
The above example does the same thing as the previous example, in a different way.
INPUT PROGRAM.
LOOP #I=1 TO 50.
COMPUTE X=UNIFORM(10).
END CASE.
END LOOP.
END FILE.
END INPUT PROGRAM.
LIST/FORMAT=NUMBERED.
The above example causes an active file to be created consisting of 50 random variates between 0 and 10.
LIST
/VARIABLES=var_list
/CASES=FROM start_index TO end_index BY incr_index
/FORMAT={UNNUMBERED,NUMBERED} {WRAP,SINGLE}
{NOWEIGHT,WEIGHT}
The LIST procedure prints the values of specified variables to the listing file.
The VARIABLES subcommand specifies the variables whose values are to be printed. Keyword VARIABLES is optional. If VARIABLES subcommand is not specified then all variables in the active file are printed.
The CASES subcommand can be used to specify a subset of cases to be printed. Specify FROM and the case number of the first case to print, TO and the case number of the last case to print, and BY and the number of cases to advance between printing cases, or any subset of those settings. If CASES is not specified then all cases are printed.
The FORMAT subcommand can be used to change the output format. NUMBERED will print case numbers along with each case; UNNUMBERED, the default, causes the case numbers to be omitted. The WRAP and SINGLE settings are currently not used. WEIGHT will cause case weights to be printed along with variable values; NOWEIGHT, the default, causes case weights to be omitted from the output.
Case numbers start from 1. They are counted after all transformations have been considered.
LIST attempts to fit all the values on a single line. If needed to make them fit, variable names are displayed vertically. If values cannot fit on a single line, then a multi-line format will be used.
LIST is a procedure. It causes the data to be read.
MATRIX DATA
/VARIABLES=var_list
/FILE='filename'
/FORMAT={LIST,FREE} {LOWER,UPPER,FULL} {DIAGONAL,NODIAGONAL}
/SPLIT={new_var,var_list}
/FACTORS=var_list
/CELLS=n_cells
/N=n
/CONTENTS={N_VECTOR,N_SCALAR,N_MATRIX,MEAN,STDDEV,COUNT,MSE,
DFE,MAT,COV,CORR,PROX}
MATRIX DATA command reads square matrices in one of several textual formats. MATRIX DATA clears the dictionary and replaces it and reads a data file.
Use VARIABLES to specify the variables that form the rows and columns of
the matrices. You may not specify a variable named VARNAME_. You
should specify VARIABLES first.
Specify the file to read on FILE, either as a file name string or a file handle (see FILE HANDLE). If FILE is not specified then matrix data must immediately follow MATRIX DATA with a BEGIN DATA...END DATA construct (see BEGIN DATA).
The FORMAT subcommand specifies how the matrices are formatted. LIST, the default, indicates that there is one line per row of matrix data; FREE allows single matrix rows to be broken across multiple lines. This is analogous to the difference between DATA LIST FREE and DATA LIST LIST (see DATA LIST). LOWER, the default, indicates that the lower triangle of the matrix is given; UPPER indicates the upper triangle; and FULL indicates that the entire matrix is given. DIAGONAL, the default, indicates that the diagonal is part of the data; NODIAGONAL indicates that it is omitted. DIAGONAL/NODIAGONAL have no effect when FULL is specified.
The SPLIT subcommand is used to specify SPLIT FILE variables for the input matrices (see SPLIT FILE). Specify either a single variable not specified on VARIABLES, or one or more variables that are specified on VARIABLES. In the former case, the SPLIT values are not present in the data and ROWTYPE_ may not be specified on VARIABLES. In the latter case, the SPLIT values are present in the data.
Specify a list of factor variables on FACTORS. Factor variables must also be listed on VARIABLES. Factor variables are used when there are some variables where, for each possible combination of their values, statistics on the matrix variables are included in the data.
If FACTORS is specified and ROWTYPE_ is not specified on VARIABLES, the CELLS subcommand is required. Specify the number of factor variable combinations that are given. For instance, if factor variable A has 2 values and factor variable B has 3 values, specify 6.
The N subcommand specifies a population number of observations. When N is specified, one N record is output for each SPLIT FILE.
Use CONTENTS to specify what sort of information the matrices include. Each possible option is described in more detail below. When ROWTYPE_ is specified on VARIABLES, CONTENTS is optional; otherwise, if CONTENTS is not specified then /CONTENTS=CORR is assumed.
The exact semantics of the matrices read by MATRIX DATA are complex. Right now MATRIX DATA isn't too useful due to a lack of procedures accepting or producing related data, so these semantics aren't documented. Later, they'll be described here in detail.
NEW FILE.
NEW FILE command clears the current active file.
PRINT
OUTFILE='filename'
RECORDS=n_lines
{NOTABLE,TABLE}
/[line_no] arg...
arg takes one of the following forms:
'string' [start-end]
var_list start-end [type_spec]
var_list (fortran_spec)
var_list *
The PRINT transformation writes variable data to an output file. PRINT is executed when a procedure causes the data to be read. Follow PRINT by EXECUTE to print variable data without invoking a procedure (see EXECUTE).
All PRINT subcommands are optional.
The OUTFILE subcommand specifies the file to receive the output. The file may be a file name as a string or a file handle (see FILE HANDLE). If OUTFILE is not present then output will be sent to PSPP's output listing file.
The RECORDS subcommand specifies the number of lines to be output. The number of lines may optionally be surrounded by parentheses.
TABLE will cause the PRINT command to output a table to the listing file that describes what it will print to the output file. NOTABLE, the default, suppresses this output table.
Introduce the strings and variables to be printed with a slash (/). Optionally, the slash may be followed by a number indicating which output line will be specified. In the absence of this line number, the next line number will be specified. Multiple lines may be specified using multiple slashes with the intended output for a line following its respective slash.
Literal strings may be printed. Specify the string itself. Optionally the string may be followed by a column number or range of column numbers, specifying the location on the line for the string to be printed. Otherwise, the string will be printed at the current position on the line.
Variables to be printed can be specified in the same ways as available for DATA LIST FIXED (see DATA LIST FIXED). In addition, a variable list may be followed by an asterisk (*), which indicates that the variables should be printed in their dictionary print formats, separated by spaces. A variable list followed by a slash or the end of command will be interpreted the same way.
If a FORTRAN type specification is used to move backwards on the current line, then text is written at that point on the line, the line will be truncated to that length, although additional text being added will again extend the line to that length.
PRINT EJECT
OUTFILE='filename'
RECORDS=n_lines
{NOTABLE,TABLE}
/[line_no] arg...
arg takes one of the following forms:
'string' [start-end]
var_list start-end [type_spec]
var_list (fortran_spec)
var_list *
PRINT EJECT writes data to an output file. Before the data is written, the current page in the listing file is ejected.
See PRINT, for more information on syntax and usage.
PRINT SPACE OUTFILE='filename' n_lines.
PRINT SPACE prints one or more blank lines to an output file.
The OUTFILE subcommand is optional. It may be used to direct output to a file specified by file name as a string or file handle (see FILE HANDLE). If OUTFILE is not specified then output will be directed to the listing file.
n_lines is also optional. If present, it is an expression (see Expressions) specifying the number of blank lines to be printed. The expression must evaluate to a nonnegative value.
REREAD FILE=handle COLUMN=column.
The REREAD transformation allows the previous input line in a data file already processed by DATA LIST or another input command to be re-read for further processing.
The FILE subcommand, which is optional, is used to specify the file to have its line re-read. The file must be specified in the form of a file handle (see FILE HANDLE). If FILE is not specified then the last file specified on DATA LIST will be assumed (last file specified lexically, not in terms of flow-of-control).
By default, the line re-read is re-read in its entirety. With the COLUMN subcommand, a prefix of the line can be exempted from re-reading. Specify an expression (see Expressions) evaluating to the first column that should be included in the re-read line. Columns are numbered from 1 at the left margin.
Issuing REREAD multiple times will not back up in the data
file. Instead, it will re-read the same line multiple times.
REPEATING DATA
/STARTS=start-end
/OCCURS=n_occurs
/FILE='filename'
/LENGTH=length
/CONTINUED[=cont_start-cont_end]
/ID=id_start-id_end=id_var
/{TABLE,NOTABLE}
/DATA=var_spec...
where each var_spec takes one of the forms
var_list start-end [type_spec]
var_list (fortran_spec)
REPEATING DATA parses groups of data repeating in a uniform format, possibly with several groups on a single line. Each group of data corresponds with one case. REPEATING DATA may only be used within an INPUT PROGRAM structure (see INPUT PROGRAM). When used with DATA LIST, it can be used to parse groups of cases that share a subset of variables but differ in their other data.
The STARTS subcommand is required. Specify a range of columns, using literal numbers or numeric variable names. This range specifies the columns on the first line that are used to contain groups of data. The ending column is optional. If it is not specified, then the record width of the input file is used. For the inline file (see BEGIN DATA) this is 80 columns; for a file with fixed record widths it is the record width; for other files it is 1024 characters by default.
The OCCURS subcommand is required. It must be a number or the name of a numeric variable. Its value is the number of groups present in the current record.
The DATA subcommand is required. It must be the last subcommand specified. It is used to specify the data present within each repeating group. Column numbers are specified relative to the beginning of a group at column 1. Data is specified in the same way as with DATA LIST FIXED (see DATA LIST FIXED).
All other subcommands are optional.
FILE specifies the file to read, either a file name as a string or a file handle (see FILE HANDLE). If FILE is not present then the default is the last file handle used on DATA LIST (lexically, not in terms of flow of control).
By default REPEATING DATA will output a table describing how it will parse the input data. Specifying NOTABLE will disable this behavior; specifying TABLE will explicitly enable it.
The LENGTH subcommand specifies the length in characters of each group. If it is not present then length is inferred from the DATA subcommand. LENGTH can be a number or a variable name.
Normally all the data groups are expected to be present on a single line. Use the CONTINUED command to indicate that data can be continued onto additional lines. If data on continuation lines starts at the left margin and continues through the entire field width, no column specifications are necessary on CONTINUED. Otherwise, specify the possible range of columns in the same way as on STARTS.
When data groups are continued from line to line, it is easy for cases to get out of sync through careless hand editing. The ID subcommand allows a case identifier to be present on each line of repeating data groups. REPEATING DATA will check for the same identifier on each line and report mismatches. Specify the range of columns that the identifier will occupy, followed by an equals sign (=) and the identifier variable name. The variable must already have been declared with NUMERIC or another command.
REPEATING DATA should be the last command given within an INPUT PROGRAM. It should not be enclosed within a LOOP structure (see LOOP). Use DATA LIST before, not after, REPEATING DATA.
WRITE
OUTFILE='filename'
RECORDS=n_lines
{NOTABLE,TABLE}
/[line_no] arg...
arg takes one of the following forms:
'string' [start-end]
var_list start-end [type_spec]
var_list (fortran_spec)
var_list *
WRITE writes text or binary data to an output file.
See PRINT, for more information on syntax and usage. The main
difference between PRINT and WRITE is that WRITE
uses write formats by default, where PRINT uses print formats.
The sole additional difference is that if WRITE is used to send output to a binary file, carriage control characters will not be output. See FILE HANDLE, for information on how to declare a file as binary.
The commands in this chapter read, write, and examine system files and portable files.
APPLY DICTIONARY FROM='filename'.
APPLY DICTIONARY applies the variable labels, value labels, and missing values from variables in a system file to corresponding variables in the active file. In some cases it also updates the weighting variable.
Specify a system file with a file name string or as a file handle (see FILE HANDLE). The dictionary in the system file will be read, but it will not replace the active file dictionary. The system file's data will not be read.
Only variables with names that exist in both the active file and the system file are considered. Variables with the same name but different types (numeric, string) will cause an error message. Otherwise, the system file variables' attributes will replace those in their matching active file variables, as described below.
If a system file variable has a variable label, then it will replace the active file variable's variable label. If the system file variable does not have a variable label, then the active file variable's variable label, if any, will be retained.
If the active file variable is numeric or short string, then value labels and missing values, if any, will be copied to the active file variable. If the system file variable does not have value labels or missing values, then those in the active file variable, if any, will not be disturbed.
Finally, weighting of the active file is updated (see WEIGHT). If the active file has a weighting variable, and the system file does not, or if the weighting variable in the system file does not exist in the active file, then the active file weighting variable, if any, is retained. Otherwise, the weighting variable in the system file becomes the active file weighting variable.
APPLY DICTIONARY takes effect immediately. It does not read the active file. The system file is not modified.
EXPORT
/OUTFILE='filename'
/DROP=var_list
/KEEP=var_list
/RENAME=(src_names=target_names)...
The EXPORT procedure writes the active file dictionary and data to a specified portable file.
The OUTFILE subcommand, which is the only required subcommand, specifies the portable file to be written as a file name string or a file handle (see FILE HANDLE).
DROP, KEEP, and RENAME follow the same format as the SAVE procedure (see SAVE).
EXPORT is a procedure. It causes the active file to be read.
GET
/FILE='filename'
/DROP=var_list
/KEEP=var_list
/RENAME=(src_names=target_names)...
GET clears the current dictionary and active file and replaces them with the dictionary and data from a specified system file.
The FILE subcommand is the only required subcommand. Specify the system file to be read as a string file name or a file handle (see FILE HANDLE).
By default, all the variables in a system file are read. The DROP subcommand can be used to specify a list of variables that are not to be read. By contrast, the KEEP subcommand can be used to specify variable that are to be read, with all other variables not read.
Normally variables in a system file retain the names that they were saved under. Use the RENAME subcommand to change these names. Specify, within parentheses, a list of variable names followed by an equals sign (=) and the names that they should be renamed to. Multiple parenthesized groups of variable names can be included on a single RENAME subcommand. Variables' names may be swapped using a RENAME subcommand of the form /RENAME=(A B=B A).
Alternate syntax for the RENAME subcommand allows the parentheses to be eliminated. When this is done, only a single variable may be renamed at once. For instance, /RENAME=A=B. This alternate syntax is deprecated.
DROP, KEEP, and RENAME are performed in left-to-right order. They each may be present any number of times. GET never modifies a system file on disk. Only the active file read from the system file is affected by these subcommands.
GET does not cause the data to be read, only the dictionary. The data is read later, when a procedure is executed.
IMPORT
/FILE='filename'
/TYPE={COMM,TAPE}
/DROP=var_list
/KEEP=var_list
/RENAME=(src_names=target_names)...
The IMPORT transformation clears the active file dictionary and data and replaces them with a dictionary and data from a portable file on disk.
The FILE subcommand, which is the only required subcommand, specifies the portable file to be read as a file name string or a file handle (see FILE HANDLE).
The TYPE subcommand is currently not used.
DROP, KEEP, and RENAME follow the syntax used by GET (see GET).
IMPORT does not cause the data to be read, only the dictionary. The data is read later, when a procedure is executed.
MATCH FILES
/{FILE,TABLE}={*,'filename'}
/DROP=var_list
/KEEP=var_list
/RENAME=(src_names=target_names)...
/IN=var_name
/BY var_list
/FIRST=var_name
/LAST=var_name
/MAP
MATCH FILES merges one or more system files, optionally including the active file. Records with the same values for BY variables are combined into a single record. Records with different values are output in order. Thus, multiple sorted system files are combined into a single sorted system file based on the value of the BY variables. The results of the merge become the new active file.
The BY subcommand specifies a list of variables that are used to match records from each of the system files. Variables specified must exist in all the files specified on FILE and TABLE. BY should usually be specified. If TABLE or IN is used then BY is required.
Specify FILE with a system file as a file name string or file handle (see FILE HANDLE), or with an asterisk (*) to indicate the current active file. The files specified on FILE are merged together based on the BY variables, or combined case-by-case if BY is not specified. Normally at least two FILE subcommands should be specified.
Specify TABLE with a system file to use it as a table lookup file. Records in table lookup files are not used up after they've been used once. This means that data in table lookup files can correspond to any number of records in FILE files. Table lookup files correspond to lookup tables in traditional relational database systems. It is incorrect to have records with duplicate BY values in table lookup files.
Any number of FILE and TABLE subcommands may be specified. Each instance of FILE or TABLE can be followed by any sequence of DROP, KEEP, or RENAME subcommands. These have the same form and meaning as the corresponding subcommands of GET (see GET), but apply only to variables in the given file.
Each FILE or TABLE may optionally be followed by an IN subcommand, which creates a numeric variable with the specified name and format F1.0. The IN variable takes value 1 in a case if the given file contributed a row to the merged file, 0 otherwise. The DROP, KEEP, and RENAME subcommands do not affect IN variables.
Variables belonging to files that are not present for the current case are set to the system-missing value for numeric variables or spaces for string variables.
FIRST, LAST, and MAP are currently ignored.
MATCH FILES may not be specified following TEMPORARY (see TEMPORARY) if the active file is used as an input source.
SAVE
/OUTFILE='filename'
/{COMPRESSED,UNCOMPRESSED}
/DROP=var_list
/KEEP=var_list
/VERSION=version
/RENAME=(src_names=target_names)...
The SAVE procedure causes the dictionary and data in the active file to be written to a system file.
OUTFILE is the only required subcommand. Specify the system file to be written as a string file name or a file handle (see FILE HANDLE).
The COMPRESS and UNCOMPRESS subcommand determine whether the saved system file is compressed. By default, system files are compressed. This default can be changed with the SET command (see SET).
By default, all the variables in the active file dictionary are written to the system file. The DROP subcommand can be used to specify a list of variables not to be written. In contrast, KEEP specifies variables to be written, with all variables not specified not written.
Normally variables are saved to a system file under the same names they have in the active file. Use the RENAME subcommand to change these names. Specify, within parentheses, a list of variable names followed by an equals sign (=) and the names that they should be renamed to. Multiple parenthesized groups of variable names can be included on a single RENAME subcommand. Variables' names may be swapped using a RENAME subcommand of the form /RENAME=(A B=B A).
Alternate syntax for the RENAME subcommand allows the parentheses to be eliminated. When this is done, only a single variable may be renamed at once. For instance, /RENAME=A=B. This alternate syntax is deprecated.
DROP, KEEP, and RENAME are performed in left-to-right order. They each may be present any number of times. SAVE never modifies the active file. DROP, KEEP, and RENAME only affect the system file written to disk.
The VERSION subcommand specifies the version of the file format. Valid versions are '3' and '3x'. Version 3x system files are identical to version 3 files, except that variable names greater than 8 bytes will be truncated. The default version is 3. The VERSION subcommand is optional. There is no need ever to use it.
SAVE causes the data to be read. It is a procedure.
SYSFILE INFO FILE='filename'.
SYSFILE INFO reads the dictionary in a system file and displays the information in its dictionary.
Specify a file name or file handle. SYSFILE INFO reads that file as a system file and displays information on its dictionary.
SYSFILE INFO does not affect the current active file.
XSAVE
/OUTFILE='filename'
/{COMPRESSED,UNCOMPRESSED}
/DROP=var_list
/KEEP=var_list
/RENAME=(src_names=target_names)...
The XSAVE transformation writes the active file dictionary and data to a system file stored on disk.
XSAVE is a transformation, not a procedure. It is executed when the data is read by a procedure or procedure-like command. In all other respects, XSAVE is identical to SAVE. See SAVE, for more information on syntax and usage.
The variables in the active file dictionary are important. There are several utility functions for examining and adjusting them.
ADD VALUE LABELS
/var_list value 'label' [value 'label']...
ADD VALUE LABELS has the same syntax and purpose as VALUE LABELS (see VALUE LABELS), but it does not clear value labels from the variables before adding the ones specified.
DISPLAY {NAMES,INDEX,LABELS,VARIABLES,DICTIONARY,SCRATCH}
[SORTED] [var_list]
DISPLAY displays requested information on variables. Variables can optionally be sorted alphabetically. The entire dictionary or just specified variables can be described.
One of the following keywords can be present:
If SORTED is specified, then the variables are displayed in ascending order based on their names; otherwise, they are displayed in the order that they occur in the active file dictionary.
DISPLAY VECTORS.
DISPLAY VECTORS lists all the currently declared vectors.
FORMATS var_list (fmt_spec).
FORMATS set both print and write formats for the specified numeric variables to the specified format specification. See Input/Output Formats.
Specify a list of variables followed by a format specification in parentheses. The print and write formats of the specified variables will be changed.
Additional lists of variables and formats may be included if they are delimited by a slash (/).
FORMATS takes effect immediately. It is not affected by conditional and looping structures such as DO IF or LOOP.
LEAVE var_list.
LEAVE prevents the specified variables from being reinitialized whenever a new case is processed.
Normally, when a data file is processed, every variable in the active file is initialized to the system-missing value or spaces at the beginning of processing for each case. When a variable has been specified on LEAVE, this is not the case. Instead, that variable is initialized to 0 (not system-missing) or spaces for the first case. After that, it retains its value between cases.
This becomes useful for counters. For instance, in the example below the variable SUM maintains a running total of the values in the ITEM variable.
DATA LIST /ITEM 1-3.
COMPUTE SUM=SUM+ITEM.
PRINT /ITEM SUM.
LEAVE SUM
BEGIN DATA.
123
404
555
999
END DATA.
Partial output from this example:
123 123.00
404 527.00
555 1082.00
999 2081.00
It is best to use LEAVE command immediately before invoking a procedure command, because the left status of variables is reset by certain transformations—for instance, COMPUTE and IF. Left status is also reset by all procedure invocations.
MISSING VALUES var_list (missing_values).
missing_values takes one of the following forms:
num1
num1, num2
num1, num2, num3
num1 THRU num2
num1 THRU num2, num3
string1
string1, string2
string1, string2, string3
As part of a range, LO or LOWEST may take the place of num1;
HI or HIGHEST may take the place of num2.
MISSING VALUES sets user-missing values for numeric and short string variables. Long string variables may not have missing values.
Specify a list of variables, followed by a list of their user-missing values in parentheses. Up to three discrete values may be given, or, for numeric variables only, a range of values optionally accompanied by a single discrete value. Ranges may be open-ended on one end, indicated through the use of the keyword LO or LOWEST or HI or HIGHEST.
The MISSING VALUES command takes effect immediately. It is not affected by conditional and looping constructs such as DO IF or LOOP.
MODIFY VARS
/REORDER={FORWARD,BACKWARD} {POSITIONAL,ALPHA} (var_list)...
/RENAME=(old_names=new_names)...
/{DROP,KEEP}=var_list
/MAP
MODIFY VARS reorders, renames, and deletes variables in the active file.
At least one subcommand must be specified, and no subcommand may be specified more than once. DROP and KEEP may not both be specified.
The REORDER subcommand changes the order of variables in the active file. Specify one or more lists of variable names in parentheses. By default, each list of variables is rearranged into the specified order. To put the variables into the reverse of the specified order, put keyword BACKWARD before the parentheses. To put them into alphabetical order in the dictionary, specify keyword ALPHA before the parentheses. BACKWARD and ALPHA may also be combined.
To rename variables in the active file, specify RENAME, an equals sign (=), and lists of the old variable names and new variable names separated by another equals sign within parentheses. There must be the same number of old and new variable names. Each old variable is renamed to the corresponding new variable name. Multiple parenthesized groups of variables may be specified.
The DROP subcommand deletes a specified list of variables from the active file.
The KEEP subcommand keeps the specified list of variables in the active file. Any unlisted variables are deleted from the active file.
MAP is currently ignored.
If either DROP or KEEP is specified, the data is read; otherwise it is not.
MODIFY VARS may not be specified following TEMPORARY (see TEMPORARY).
NUMERIC /var_list [(fmt_spec)].
NUMERIC explicitly declares new numeric variables, optionally setting their output formats.
Specify a slash (/), followed by the names of the new numeric variables. If you wish to set their output formats, follow their names by an output format specification in parentheses (see Input/Output Formats); otherwise, the default is F8.2.
Variables created with NUMERIC are initialized to the system-missing value.
PRINT FORMATS var_list (fmt_spec).
PRINT FORMATS sets the print formats for the specified numeric variables to the specified format specification.
Its syntax is identical to that of FORMATS (see FORMATS), but PRINT FORMATS sets only print formats, not write formats.
RENAME VARIABLES (old_names=new_names)... .
RENAME VARIABLES changes the names of variables in the active file. Specify lists of the old variable names and new variable names, separated by an equals sign (=), within parentheses. There must be the same number of old and new variable names. Each old variable is renamed to the corresponding new variable name. Multiple parenthesized groups of variables may be specified.
RENAME VARIABLES takes effect immediately. It does not cause the data to be read.
RENAME VARIABLES may not be specified following TEMPORARY (see TEMPORARY).
VALUE LABELS
/var_list value 'label' [value 'label']...
VALUE LABELS allows values of numeric and short string variables to be associated with labels. In this way, a short value can stand for a long value.
To set up value labels for a set of variables, specify the variable names after a slash (/), followed by a list of values and their associated labels, separated by spaces. Long string variables may not be specified.
Before VALUE LABELS is executed, any existing value labels are cleared from the variables specified. Use ADD VALUE LABELS (see ADD VALUE LABELS) to add value labels without clearing those already present.
STRING /var_list (fmt_spec).
STRING creates new string variables for use in transformations.
Specify a slash (/), followed by the names of the string variables to create and the desired output format specification in parentheses (see Input/Output Formats). Variable widths are implicitly derived from the specified output formats.
Created variables are initialized to spaces.
VARIABLE LABELS
var_list 'var_label'
[ /var_list 'var_label']
.
.
.
[ /var_list 'var_label']
VARIABLE LABELS associates explanatory names with variables. This name, called a variable label, is displayed by statistical procedures.
To assign a variable label to a group of variables, specify a list of variable names and the variable label as a string. To assign different labels to different variables in the same command, preceed the subsequent variable list with a slash (/).
VARIABLE ALIGNMENT
var_list ( LEFT | RIGHT | CENTER )
[ /var_list ( LEFT | RIGHT | CENTER ) ]
.
.
.
[ /var_list ( LEFT | RIGHT | CENTER ) ]
VARIABLE ALIGNMENT sets the alignment of variables for display editing purposes. This only has effect for third party software. It does not affect the display of variables in the PSPP output.
VARIABLE WIDTH
var_list (width)
[ /var_list (width) ]
.
.
.
[ /var_list (width) ]
VARIABLE WIDTH sets the column width of variables for display editing purposes. This only affects third party software. It does not affect the display of variables in the PSPP output.
VARIABLE LEVEL
var_list ( SCALE | NOMINAL | ORDINAL )
[ /var_list ( SCALE | NOMINAL | ORDINAL ) ]
.
.
.
[ /var_list ( SCALE | NOMINAL | ORDINAL ) ]
VARIABLE LEVEL sets the measurement level of variables. Currently, this has no effect except for certain third party software.
Two possible syntaxes:
VECTOR vec_name=var_list.
VECTOR vec_name_list(count).
VECTOR allows a group of variables to be accessed as if they were consecutive members of an array with a vector(index) notation.
To make a vector out of a set of existing variables, specify a name for the vector followed by an equals sign (=) and the variables that belong in the vector.
To make a vector and create variables at the same time, specify one or
more vector names followed by a count in parentheses. This will cause
variables named vec1 through veccount
to be created as numeric variables with print and write format F8.2.
Variable names including numeric suffixes may not exceed 64 characters
in length, and none of the variables may exist prior to VECTOR.
All the variables in a vector must be the same type.
Vectors created with VECTOR disappear after any procedure or procedure-like command is executed. The variables contained in the vectors remain, unless they are scratch variables (see Scratch Variables).
Variables within a vector may be referenced in expressions using
vector(index) syntax.
WRITE FORMATS var_list (fmt_spec).
WRITE FORMATS sets the write formats for the specified numeric variables to the specified format specification. Its syntax is identical to that of FORMATS (see FORMATS), but WRITE FORMATS sets only write formats, not print formats.
The PSPP procedures examined in this chapter manipulate data and prepare the active file for later analyses. They do not produce output, as a rule.
AGGREGATE
OUTFILE={*,'filename'}
/PRESORTED
/DOCUMENT
/MISSING=COLUMNWISE
/BREAK=var_list
/dest_var['label']...=agr_func(src_vars, args...)...
AGGREGATE summarizes groups of cases into single cases. Cases are divided into groups that have the same values for one or more variables called break variables. Several functions are available for summarizing case contents.
The OUTFILE subcommand is required and must appear first. Specify a system file by file name string or file handle (see FILE HANDLE). The aggregated cases are written to this file. If * is specified, then the aggregated cases replace the active file.
By default, the active file will be sorted based on the break variables before aggregation takes place. If the active file is already sorted or otherwise grouped in terms of the break variables, specify PRESORTED to save time.
Specify DOCUMENT to copy the documents from the active file into the aggregate file (see DOCUMENT). Otherwise, the aggregate file will not contain any documents, even if the aggregate file replaces the active file.
Normally, only a single case (for SD and SD., two cases) need be non-missing in each group for the aggregate variable to be non-missing. Specifying /MISSING=COLUMNWISE inverts this behavior, so that the aggregate variable becomes missing if any aggregated value is missing.
If PRESORTED, DOCUMENT, or MISSING are specified, they must appear between OUTFILE and BREAK.
At least one break variable must be specified on BREAK, a required subcommand. The values of these variables are used to divide the active file into groups to be summarized. In addition, at least one dest_var must be specified.
One or more sets of aggregation variables must be specified. Each set comprises a list of aggregation variables, an equals sign (=), the name of an aggregation function (see the list below), and a list of source variables in parentheses. Some aggregation functions expect additional arguments following the source variable names.
Aggregation variables typically are created with no variable label, value labels, or missing values. Their default print and write formats depend on the aggregation function used, with details given in the table below. A variable label for an aggregation variable may be specified just after the variable's name in the aggregation variable list.
Each set must have exactly as many source variables as aggregation variables. Each aggregation variable receives the results of applying the specified aggregation function to the corresponding source variable. The MEAN, SD, and SUM aggregation functions may only be applied to numeric variables. All the rest may be applied to numeric and short and long string variables.
The available aggregation functions are as follows:
Aggregation functions compare string values in terms of internal character codes. On most modern computers, this is a form of ASCII.
The aggregation functions listed above exclude all user-missing values from calculations. To include user-missing values, insert a period (.) at the end of the function name. (e.g. SUM.). (Be aware that specifying such a function as the last token on a line will cause the period to be interpreted as the end of the command.)
AGGREGATE both ignores and cancels the current SPLIT FILE settings (see SPLIT FILE).
AUTORECODE VARIABLES=src_vars INTO dest_vars
/DESCENDING
/PRINT
The AUTORECODE procedure considers the n values that a variable takes on and maps them onto values 1...n on a new numeric variable.
Subcommand VARIABLES is the only required subcommand and must come first. Specify VARIABLES, an equals sign (=), a list of source variables, INTO, and a list of target variables. There must the same number of source and target variables. The target variables must not already exist.
By default, increasing values of a source variable (for a string, this is based on character code comparisons) are recoded to increasing values of its target variable. To cause increasing values of a source variable to be recoded to decreasing values of its target variable (n down to 1), specify DESCENDING.
PRINT is currently ignored.
AUTORECODE is a procedure. It causes the data to be read.
COMPUTE variable = expression.
or
COMPUTE vector(index) = expression.
COMPUTE assigns the value of an expression to a target variable. For each case, the expression is evaluated and its value assigned to the target variable. Numeric and short and long string variables may be assigned. When a string expression's width differs from the target variable's width, the string result of the expression is truncated or padded with spaces on the right as necessary. The expression and variable types must match.
For numeric variables only, the target variable need not already
exist. Numeric variables created by COMPUTE are assigned an
F8.2 output format. String variables must be declared before
they can be used as targets for COMPUTE.
The target variable may be specified as an element of a vector (see VECTOR). In this case, a vector index expression must be specified in parentheses following the vector name. The index expression must evaluate to a numeric value that, after rounding down to the nearest integer, is a valid index for the named vector.
Using COMPUTE to assign to a variable specified on LEAVE
(see LEAVE) resets the variable's left state. Therefore,
LEAVE should be specified following COMPUTE, not before.
COMPUTE is a transformation. It does not cause the active file to be read.
When COMPUTE is specified following TEMPORARY (see TEMPORARY), the LAG function may not be used (see LAG).
COUNT var_name = var... (value...).
Each value takes one of the following forms:
number
string
num1 THRU num2
MISSING
SYSMIS
In addition, num1 and num2 can be LO or LOWEST, or HI or HIGHEST,
respectively.
COUNT creates or replaces a numeric target variable that counts the occurrence of a criterion value or set of values over one or more test variables for each case.
The target variable values are always nonnegative integers. They are never missing. The target variable is assigned an F8.2 output format. See Input/Output Formats. Any variables, including long and short string variables, may be test variables.
User-missing values of test variables are treated just like any other values. They are not treated as system-missing values. User-missing values that are criterion values or inside ranges of criterion values are counted as any other values. However (for numeric variables), keyword MISSING may be used to refer to all system- and user-missing values.
COUNT target variables are assigned values in the order
specified. In the command COUNT A=A B(1) /B=A B(2)., the
following actions occur:
A and B is counted.
A is assigned this value.
B and the new
value of A is counted.
B is assigned this value.
Despite this ordering, all COUNT criterion variables must exist before the procedure is executed—they may not be created as target variables earlier in the command! Break such a command into two separate commands.
The examples below may help to clarify.
Q0, Q2, ..., Q9 are numeric variables,
the following commands:
QCOUNT.
COUNT QCOUNT=Q0 TO Q9(1).
DESCRIPTIVES QCOUNT /STATISTICS=SUM.
QVALID.
QVALID by 10 to obtain a percentage of
valid values, using COMPUTE. See COMPUTE, for details.
COUNT QVALID=Q0 TO Q9 (LO THRU HI).
COMPUTE QVALID=QVALID*10.
DESCRIPTIVES QVALID /STATISTICS=MEAN.
FLIP /VARIABLES=var_list /NEWNAMES=var_name.
FLIP transposes rows and columns in the active file. It causes cases to be swapped with variables, and vice versa.
All variables in the transposed active file are numeric. String variables take on the system-missing value in the transposed file.
No subcommands are required. If specified, the VARIABLES subcommand selects variables to be transformed into cases, and variables not specified are discarded. If the VARIABLES subcommand is omitted, all variables are selected for transposition.
The variables specified by NEWNAMES, which must be a string variable, is used to give names to the variables created by FLIP. Only the first 8 characters of the variable are used. If NEWNAMES is not specified then the default is a variable named CASE_LBL, if it exists. If it does not then the variables created by FLIP are named VAR000 through VAR999, then VAR1000, VAR1001, and so on.
When a NEWNAMES variable is available, the names must be canonicalized before becoming variable names. Invalid characters are replaced by letter V in the first position, or by _ in subsequent positions. If the name thus generated is not unique, then numeric extensions are added, starting with 1, until a unique name is found or there are no remaining possibilities. If the latter occurs then the FLIP operation aborts.
The resultant dictionary contains a CASE_LBL variable, a string variable of width 8, which stores the names of the variables in the dictionary before the transposition. Variables names longer than 8 characters are truncated. If the active file is subsequently transposed using FLIP, this variable can be used to recreate the original variable names.
FLIP honors N OF CASES (see N OF CASES). It ignores TEMPORARY (see TEMPORARY), so that “temporary” transformations become permanent.
IF condition variable=expression.
or
IF condition vector(index)=expression.
The IF transformation conditionally assigns the value of a target expression to a target variable, based on the truth of a test expression.
Specify a boolean-valued expression (see Expressions) to be tested following the IF keyword. This expression is evaluated for each case. If the value is true, then the value of the expression is computed and assigned to the specified variable. If the value is false or missing, nothing is done. Numeric and short and long string variables may be assigned. When a string expression's width differs from the target variable's width, the string result of the expression is truncated or padded with spaces on the right as necessary. The expression and variable types must match.
The target variable may be specified as an element of a vector (see VECTOR). In this case, a vector index expression must be specified in parentheses following the vector name. The index expression must evaluate to a numeric value that, after rounding down to the nearest integer, is a valid index for the named vector.
Using IF to assign to a variable specified on LEAVE
(see LEAVE) resets the variable's left state. Therefore,
LEAVE should be specified following IF, not before.
When IF is specified following TEMPORARY (see TEMPORARY), the LAG function may not be used (see LAG).
RECODE var_list (src_value...=dest_value)... [INTO var_list].
src_value may take the following forms:
number
string
num1 THRU num2
MISSING
SYSMIS
ELSE
Open-ended ranges may be specified using LO or LOWEST for num1
or HI or HIGHEST for num2.
dest_value may take the following forms:
num
string
SYSMIS
COPY
RECODE translates data from one range of values to another, via flexible user-specified mappings. Data may be remapped in-place or copied to new variables. Numeric, short string, and long string data can be recoded.
Specify the list of source variables, followed by one or more mapping specifications each enclosed in parentheses. If the data is to be copied to new variables, specify INTO, then the list of target variables. String target variables must already have been declared using STRING or another transformation, but numeric target variables can be created on the fly. There must be exactly as many target variables as source variables. Each source variable is remapped into its corresponding target variable.
When INTO is not used, the input and output variables must be of the same type. Otherwise, string values can be recoded into numeric values, and vice versa. When this is done and there is no mapping for a particular value, either a value consisting of all spaces or the system-missing value is assigned, depending on variable type.
Mappings are considered from left to right. The first src_value that matches the value of the source variable causes the target variable to receive the value indicated by the dest_value. Literal number, string, and range src_value's should be self-explanatory. MISSING as a src_value matches any user- or system-missing value. SYSMIS matches the system missing value only. ELSE is a catch-all that matches anything. It should be the last src_value specified.
Numeric and string dest_value's should also be self-explanatory. COPY causes the input values to be copied to the output. This is only value if the source and target variables are of the same type. SYSMIS indicates the system-missing value.
If the source variables are strings and the target variables are numeric, then there is one additional mapping available: (CONVERT), which must be the last specified mapping. CONVERT causes a number specified as a string to be converted to a numeric value. If the string cannot be parsed as a number, then the system-missing value is assigned.
Multiple recodings can be specified on a single RECODE invocation. Introduce additional recodings with a slash (/) to separate them from the previous recodings.
SORT CASES BY var_list.
SORT CASES sorts the active file by the values of one or more variables.
Specify BY and a list of variables to sort by. By default, variables are sorted in ascending order. To override sort order, specify (D) or (DOWN) after a list of variables to get descending order, or (A) or (UP) for ascending order. These apply to the entire list of variables preceding them.
The sort algorithms used by SORT CASES are stable. That is, records that have equal values of the sort variables will have the same relative order before and after sorting. As a special case, re-sorting an already sorted file will not affect the ordering of cases.
SORT CASES is a procedure. It causes the data to be read.
SORT CASES attempts to sort the entire active file in main memory. If workspace is exhausted, it falls back to a merge sort algorithm that involves creates numerous temporary files.
SORT CASES may not be specified following TEMPORARY.
This chapter documents PSPP commands that temporarily or permanently select data records from the active file for analysis.
FILTER BY var_name.
FILTER OFF.
FILTER allows a boolean-valued variable to be used to select cases from the data stream for processing.
To set up filtering, specify BY and a variable name. Keyword BY is optional but recommended. Cases which have a zero or system- or user-missing value are excluded from analysis, but not deleted from the data stream. Cases with other values are analyzed. To filter based on a different condition, use transformations such as COMPUTE or RECODE to compute a filter variable of the required form, then specify that variable on FILTER.
FILTER OFF turns off case filtering.
Filtering takes place immediately before cases pass to a procedure for
analysis. Only one filter variable may be active at a time. Normally,
case filtering continues until it is explicitly turned off with FILTER
OFF. However, if FILTER is placed after TEMPORARY, it filters only
the next procedure or procedure-like command.
N [OF CASES] num_of_cases [ESTIMATED].
Sometimes you may want to disregard cases of your input. N can
do this. N 100 tells PSPP to disregard all cases after the
first 100.
If the value specified for N is greater than the number of cases read in, the value is ignored.
N does not discard cases or prevent them from being read. It just causes cases beyond the last one specified to be ignored by data analysis commands.
A later N command can increase or decrease the number of cases selected. (To select all the cases without knowing how many there are, specify a very high number: 100000 or whatever you think is large enough.)
Transformation procedures performed after N is executed do cause cases to be discarded.
SAMPLE, PROCESS IF, and SELECT IF have precedence over N—the same results are obtained by both of the following fragments, given the same random number seeds:
...set up, read in data...
N 100.
SAMPLE .5.
...analyze data...
...set up, read in data...
SAMPLE .5.
N 100.
...analyze data...
Both fragments above first randomly sample approximately half of the cases, then select the first 100 of those sampled.
N with the ESTIMATED keyword gives an
estimated number of cases before DATA LIST or another command to
read in data. ESTIMATED never limits the number of cases
processed by procedures. PSPP currently does not make use of
case count estimates.
When N is specified after TEMPORARY, it affects only the next procedure (see TEMPORARY).
PROCESS IF expression.
PROCESS IF temporarily eliminates cases from the data stream. Its effects are active only through the execution of the next procedure or procedure-like command.
Specify a boolean expression (see Expressions). If the value of the expression is true for a particular case, the case will be analyzed. If the expression has a false or missing value, then the case will be deleted from the data stream for this procedure only.
Regardless of its placement relative to other commands, PROCESS IF always takes effect immediately before data passes to the procedure. Only one PROCESS IF command may be in effect at any given time.
The effects of PROCESS IF are similar, but not identical, to the effects of executing TEMPORARY, then SELECT IF (see SELECT IF).
The filtering performed by PROCESS IF takes place immediately before cases pass to a procedure for analysis. Because PROCESS IF affects only a single procedure, its placement relative to TEMPORARY is unimportant.
PROCESS IF is deprecated. It is included for compatibility with old command files. New syntax files should use SELECT IF or FILTER instead.
SAMPLE num1 [FROM num2].
SAMPLE randomly samples a proportion of the cases in the active file. Unless it follows TEMPORARY, it operates as a transformation, permanently removing cases from the active file.
The proportion to sample can be expressed as a single number between 0
and 1. If k is the number specified, and N is the number
of currently-selected cases in the active file, then after
SAMPLE k., approximately k*N cases will be
selected.
The proportion to sample can also be specified in the style SAMPLE
m FROM N. With this style, cases are selected as follows:
SAMPLE and SELECT IF are performed in the order specified by the syntax file.
SAMPLE is always performed before N OF CASES, regardless
of ordering in the syntax file (see N OF CASES).
The same values for SAMPLE may result in different samples. To
obtain the same sample, use the SET command to set the random
number seed to the same value before each SAMPLE. Different
samples may still result when the file is processed on systems with
differing endianness or floating-point formats. By default, the
random number seed is based on the system time.
SELECT IF expression.
SELECT IF selects cases for analysis based on the value of a boolean expression. Cases not selected are permanently eliminated from the active file, unless TEMPORARY is in effect (see TEMPORARY).
Specify a boolean expression (see Expressions). If the value of the expression is true for a particular case, the case will be analyzed. If the expression has a false or missing value, then the case will be deleted from the data stream.
Place SELECT IF as early in the command file as possible. Cases that are deleted early can be processed more efficiently in time and space.
When SELECT IF is specified following TEMPORARY (see TEMPORARY), the LAG function may not be used (see LAG).
SPLIT FILE [{LAYERED, SEPARATE}] BY var_list.
SPLIT FILE OFF.
SPLIT FILE allows multiple sets of data present in one data file to be analyzed separately using single statistical procedure commands.
Specify a list of variable names to analyze multiple sets of data separately. Groups of adjacent cases having the same values for these variables are analyzed by statistical procedure commands as one group. An independent analysis is carried out for each group of cases, and the variable values for the group are printed along with the analysis.
When a list of variable names is specified, one of the keywords LAYERED or SEPARATE may also be specified. If provided, either keyword are ignored.
Groups are formed only by adjacent cases. To create a split using a variable where like values are not adjacent in the working file, you should first sort the data by that variable (see SORT CASES).
Specify OFF to disable SPLIT FILE and resume analysis of the entire active file as a single group of data.
When SPLIT FILE is specified after TEMPORARY, it affects only the next procedure (see TEMPORARY).
TEMPORARY.
TEMPORARY is used to make the effects of transformations following its execution temporary. These transformations will affect only the execution of the next procedure or procedure-like command. Their effects will not be saved to the active file.
The only specification on TEMPORARY is the command name.
TEMPORARY may not appear within a DO IF or LOOP construct. It may appear only once between procedures and procedure-like commands.
Scratch variables cannot be used following TEMPORARY.
An example may help to clarify:
DATA LIST /X 1-2.
BEGIN DATA.
2
4
10
15
20
24
END DATA.
COMPUTE X=X/2.
TEMPORARY.
COMPUTE X=X+3.
DESCRIPTIVES X.
DESCRIPTIVES X.
The data read by the first DESCRIPTIVES are 4, 5, 8, 10.5, 13, 15. The data read by the first DESCRIPTIVES are 1, 2, 5, 7.5, 10, 12.
WEIGHT BY var_name.
WEIGHT OFF.
WEIGHT assigns cases varying weights, changing the frequency distribution of the active file. Execution of WEIGHT is delayed until data have been read.
If a variable name is specified, WEIGHT causes the values of that variable to be used as weighting factors for subsequent statistical procedures. Use of keyword BY is optional but recommended. Weighting variables must be numeric. Scratch variables may not be used for weighting (see Scratch Variables).
When OFF is specified, subsequent statistical procedures will weight all cases equally.
A positive integer weighting factor w on a case will yield the same statistical output as would replicating the case w times. A weighting factor of 0 is treated for statistical purposes as if the case did not exist in the input. Weighting values need not be integers, but negative and system-missing values for the weighting variable are interpreted as weighting factors of 0. User-missing values are not treated specially.
When WEIGHT is specified after TEMPORARY, it affects only the next procedure (see TEMPORARY).
WEIGHT does not cause cases in the active file to be replicated in memory.
This chapter documents PSPP commands used for conditional execution, looping, and flow of control.
BREAK.
BREAK terminates execution of the innermost currently executing LOOP construct.
BREAK is allowed only inside LOOP...END LOOP. See LOOP, for more details.
DO IF condition.
...
[ELSE IF condition.
...
]...
[ELSE.
...]
END IF.
DO IF allows one of several sets of transformations to be executed, depending on user-specified conditions.
If the specified boolean expression evaluates as true, then the block of code following DO IF is executed. If it evaluates as missing, then none of the code blocks is executed. If it is false, then the boolean expression on the first ELSE IF, if present, is tested in turn, with the same rules applied. If all expressions evaluate to false, then the ELSE code block is executed, if it is present.
When DO IF or ELSE IF is specified following TEMPORARY (see TEMPORARY), the LAG function may not be used (see LAG).
DO REPEAT repvar_name=expansion....
...
END REPEAT [PRINT].
expansion takes one of the following forms:
var_list
num_or_range...
'string'...
num_or_range takes one of the following forms:
number
num1 TO num2
DO REPEAT repeats a block of code, textually substituting different variables, numbers, or strings into the block with each repetition.
Specify a repeat variable name followed by an equals sign (=) and the list of replacements. Replacements can be a list of variables (which may be existing variables or new variables or a combination thereof), of numbers, or of strings. When new variable names are specified, DO REPEAT creates them as numeric variables. When numbers are specified, runs of integers may be indicated with TO notation, for instance 1 TO 5 and 1 2 3 4 5 would be equivalent. There is no equivalent notation for string values.
Multiple repeat variables can be specified. When this is done, each variable must have the same number of replacements.
The code within DO REPEAT is repeated as many times as there are replacements for each variable. The first time, the first value for each repeat variable is substituted; the second time, the second value for each repeat variable is substituted; and so on.
Repeat variable substitutions work like macros. They take place anywhere in a line that the repeat variable name occurs as a token, including command and subcommand names. For this reason it is not a good idea to select words commonly used in command and subcommand names as repeat variable identifiers.
If PRINT is specified on END REPEAT, the commands after substitutions are made are printed to the listing file, prefixed by a plus sign (+).
LOOP [index_var=start TO end [BY incr]] [IF condition].
...
END LOOP [IF condition].
LOOP iterates a group of commands. A number of termination options are offered.
Specify index_var to make that variable count from one value to another by a particular increment. index_var must be a pre-existing numeric variable. start, end, and incr are numeric expressions (see Expressions.)
During the first iteration, index_var is set to the value of start. During each successive iteration, index_var is increased by the value of incr. If end > start, then the loop terminates when index_var > end; otherwise it terminates when index_var < end. If incr is not specified then it defaults to +1 or -1 as appropriate.
If end > start and incr < 0, or if end < start and incr > 0, then the loop is never executed. index_var is nevertheless set to the value of start.
Modifying index_var within the loop is allowed, but it has no effect on the value of index_var in the next iteration.
Specify a boolean expression for the condition on LOOP to cause the loop to be executed only if the condition is true. If the condition is false or missing before the loop contents are executed the first time, the loop contents are not executed at all.
If index and condition clauses are both present on LOOP, the index clause is always evaluated first.
Specify a boolean expression for the condition on END LOOP to cause the loop to terminate if the condition is not true after the enclosed code block is executed. The condition is evaluated at the end of the loop, not at the beginning.
If the index clause and both condition clauses are not present, then the loop is executed MXLOOPS (see SET) times.
BREAK also terminates LOOP execution (see BREAK).
Loop index variables are by default reset to system-missing from one case to another, not left, unless a scratch variable is used as index. When loops are nested, this is usually undesired behavior, which can be corrected with LEAVE (see LEAVE) or by using a scratch variable as the loop index.
When LOOP or END LOOP is specified following TEMPORARY (see TEMPORARY), the LAG function may not be used (see LAG).
This chapter documents the statistical procedures that PSPP supports so far.
DESCRIPTIVES
/VARIABLES=var_list
/MISSING={VARIABLE,LISTWISE} {INCLUDE,NOINCLUDE}
/FORMAT={LABELS,NOLABELS} {NOINDEX,INDEX} {LINE,SERIAL}
/SAVE
/STATISTICS={ALL,MEAN,SEMEAN,STDDEV,VARIANCE,KURTOSIS,
SKEWNESS,RANGE,MINIMUM,MAXIMUM,SUM,DEFAULT,
SESKEWNESS,SEKURTOSIS}
/SORT={NONE,MEAN,SEMEAN,STDDEV,VARIANCE,KURTOSIS,SKEWNESS,
RANGE,MINIMUM,MAXIMUM,SUM,SESKEWNESS,SEKURTOSIS,NAME}
{A,D}
The DESCRIPTIVES procedure reads the active file and outputs descriptive statistics requested by the user. In addition, it can optionally compute Z-scores.
The VARIABLES subcommand, which is required, specifies the list of variables to be analyzed. Keyword VARIABLES is optional.
All other subcommands are optional:
The MISSING subcommand determines the handling of missing variables. If INCLUDE is set, then user-missing values are included in the calculations. If NOINCLUDE is set, which is the default, user-missing values are excluded. If VARIABLE is set, then missing values are excluded on a variable by variable basis; if LISTWISE is set, then the entire case is excluded whenever any value in that case has a system-missing or, if INCLUDE is set, user-missing value.
The FORMAT subcommand affects the output format. Currently the LABELS/NOLABELS and NOINDEX/INDEX settings are not used. When SERIAL is set, both valid and missing number of cases are listed in the output; when NOSERIAL is set, only valid cases are listed.
The SAVE subcommand causes DESCRIPTIVES to calculate Z scores for all the specified variables. The Z scores are saved to new variables. Variable names are generated by trying first the original variable name with Z prepended and truncated to a maximum of 8 characters, then the names ZSC000 through ZSC999, STDZ00 through STDZ09, ZZZZ00 through ZZZZ09, ZQZQ00 through ZQZQ09, in that sequence. In addition, Z score variable names can be specified explicitly on VARIABLES in the variable list by enclosing them in parentheses after each variable.
The STATISTICS subcommand specifies the statistics to be displayed:
ALLMEANSEMEANSTDDEVVARIANCEKURTOSISSKEWNESSRANGEMINIMUMMAXIMUMSUMDEFAULTSEKURTOSISSESKEWNESSThe SORT subcommand specifies how the statistics should be sorted. Most of the possible values should be self-explanatory. NAME causes the statistics to be sorted by name. By default, the statistics are listed in the order that they are specified on the VARIABLES subcommand. The A and D settings request an ascending or descending sort order, respectively.
FREQUENCIES
/VARIABLES=var_list
/FORMAT={TABLE,NOTABLE,LIMIT(limit)}
{STANDARD,CONDENSE,ONEPAGE[(onepage_limit)]}
{LABELS,NOLABELS}
{AVALUE,DVALUE,AFREQ,DFREQ}
{SINGLE,DOUBLE}
{OLDPAGE,NEWPAGE}
/MISSING={EXCLUDE,INCLUDE}
/STATISTICS={DEFAULT,MEAN,SEMEAN,MEDIAN,MODE,STDDEV,VARIANCE,
KURTOSIS,SKEWNESS,RANGE,MINIMUM,MAXIMUM,SUM,
SESKEWNESS,SEKURTOSIS,ALL,NONE}
/NTILES=ntiles
/PERCENTILES=percent...
(These options are not currently implemented.)
/BARCHART=...
/HISTOGRAM=...
/HBAR=...
/GROUPED=...
(Integer mode.)
/VARIABLES=var_list (low,high)...
The FREQUENCIES procedure outputs frequency tables for specified variables. FREQUENCIES can also calculate and display descriptive statistics (including median and mode) and percentiles.
In the future, FREQUENCIES will also support graphical output in the form of bar charts and histograms. In addition, it will be able to support percentiles for grouped data.
The VARIABLES subcommand is the only required subcommand. Specify the variables to be analyzed. In most cases, this is all that is required. This is known as general mode.
Occasionally, one may want to invoke a special mode called integer mode. Normally, in general mode, PSPP will automatically determine what values occur in the data. In integer mode, the user specifies the range of values that the data assumes. To invoke this mode, specify a range of data values in parentheses, separated by a comma. Data values inside the range are truncated to the nearest integer, then assigned to that value. If values occur outside this range, they are discarded.
The FORMAT subcommand controls the output format. It has several possible settings:
The MISSING subcommand controls the handling of user-missing values. When EXCLUDE, the default, is set, user-missing values are not included in frequency tables or statistics. When INCLUDE is set, user-missing are included. System-missing values are never included in statistics, but are listed in frequency tables.
The available STATISTICS are the same as available in DESCRIPTIVES (see DESCRIPTIVES), with the addition of MEDIAN, the data's median value, and MODE, the mode. (If there are multiple modes, the smallest value is reported.) By default, the mean, standard deviation of the mean, minimum, and maximum are reported for each variable.
PERCENTILES causes the specified percentiles to be reported.
The percentiles should be presented at a list of numbers between 0
and 100 inclusive.
The NTILES subcommand causes the percentiles to be reported at the
boundaries of the data set divided into the specified number of ranges.
For instance, /NTILES=4 would cause quartiles to be reported.
EXAMINE
VARIABLES=var_list [BY factor_list ]
/STATISTICS={DESCRIPTIVES, EXTREME[(n)], ALL, NONE}
/PLOT={STEMLEAF, BOXPLOT, NPPLOT, SPREADLEVEL(n), HISTOGRAM,
ALL, NONE}
/CINTERVAL n
/COMPARE={GROUPS,VARIABLES}
/ID={case_number, var_name}
/{TOTAL,NOTOTAL}
/PERCENTILE=[value_list]={HAVERAGE, WAVERAGE, ROUND, AEMPIRICAL, EMPIRICAL }
/MISSING={LISTWISE, PAIRWISE} [{EXCLUDE, INCLUDE}]
[{NOREPORT,REPORT}]
The EXAMINE command is used to test how closely a distribution is to a normal distribution. It also shows you outliers and extreme values.
The VARIABLES subcommand specifies the dependent variables and the independent variable to use as factors for the analysis. Variables listed before the first BY keyword are the dependent variables. The dependent variables may optionally be followed by a list of factors which tell PSPP how to break down the analysis for each dependent variable. The format for each factor is
var [BY var].
The STATISTICS subcommand specifies the analysis to be done. DESCRIPTIVES will produce a table showing some parametric and non-parametrics statistics. EXTREME produces a table showing extreme values of the dependent variable. A number in parentheses determines how many upper and lower extremes to show. The default number is 5.
The PLOT subcommand specifies which plots are to be produced if any.
The COMPARE subcommand is only relevant if producing boxplots, and it is only useful there is more than one dependent variable and at least one factor. If /COMPARE=GROUPS is specified, then one plot per dependent variable is produced, containing boxplots for all the factors. If /COMPARE=VARIABLES is specified, then one plot per factor is produced, each each containing one boxplot per dependent variable. If the /COMPARE subcommand is ommitted, then PSPP uses the default value of /COMPARE=GROUPS.
The CINTERVAL subcommand specifies the confidence interval to use in calculation of the descriptives command. The default it 95%.
The PERCENTILES subcommand specifies which percentiles are to be calculated, and which algorithm to use for calculating them. The default is to calculate the 5, 10, 25, 50, 75, 90, 95 percentiles using the HAVERAGE algorithm.
The TOTAL and NOTOTAL subcommands are mutually exclusive. If NOTOTAL is given and factors have been specified in the VARIABLES subcommand, then then statistics for the unfactored dependent variables are produced in addition to the factored variables. If there are no factors specified then TOTAL and NOTOTAL have no effect.
Warning! If many dependent variable are given, or factors are given for which there are many distinct values, then EXAMINE will produce a very large quantity of output.
CROSSTABS
/TABLES=var_list BY var_list [BY var_list]...
/MISSING={TABLE,INCLUDE,REPORT}
/WRITE={NONE,CELLS,ALL}
/FORMAT={TABLES,NOTABLES}
{LABELS,NOLABELS,NOVALLABS}
{PIVOT,NOPIVOT}
{AVALUE,DVALUE}
{NOINDEX,INDEX}
{BOX,NOBOX}
/CELLS={COUNT,ROW,COLUMN,TOTAL,EXPECTED,RESIDUAL,SRESIDUAL,
ASRESIDUAL,ALL,NONE}
/STATISTICS={CHISQ,PHI,CC,LAMBDA,UC,BTAU,CTAU,RISK,GAMMA,D,
KAPPA,ETA,CORR,ALL,NONE}
(Integer mode.)
/VARIABLES=var_list (low,high)...
The CROSSTABS procedure displays crosstabulation tables requested by the user. It can calculate several statistics for each cell in the crosstabulation tables. In addition, a number of statistics can be calculated for each table itself.
The TABLES subcommand is used to specify the tables to be reported. Any number of dimensions is permitted, and any number of variables per dimension is allowed. The TABLES subcommand may be repeated as many times as needed. This is the only required subcommand in general mode.
Occasionally, one may want to invoke a special mode called integer mode. Normally, in general mode, PSPP automatically determines what values occur in the data. In integer mode, the user specifies the range of values that the data assumes. To invoke this mode, specify the VARIABLES subcommand, giving a range of data values in parentheses for each variable to be used on the TABLES subcommand. Data values inside the range are truncated to the nearest integer, then assigned to that value. If values occur outside this range, they are discarded. When it is present, the VARIABLES subcommand must precede the TABLES subcommand.
In general mode, numeric and string variables may be specified on TABLES. Although long string variables are allowed, only their initial short-string parts are used. In integer mode, only numeric variables are allowed.
The MISSING subcommand determines the handling of user-missing values. When set to TABLE, the default, missing values are dropped on a table by table basis. When set to INCLUDE, user-missing values are included in tables and statistics. When set to REPORT, which is allowed only in integer mode, user-missing values are included in tables but marked with an M (for “missing”) and excluded from statistical calculations.
Currently the WRITE subcommand is ignored.
The FORMAT subcommand controls the characteristics of the crosstabulation tables to be displayed. It has a number of possible settings:
The CELLS subcommand controls the contents of each cell in the displayed crosstabulation table. The possible settings are:
/CELLS without any settings specified requests COUNT, ROW, COLUMN, and TOTAL. If CELLS is not specified at all then only COUNT will be selected.
The STATISTICS subcommand selects statistics for computation:
Selected statistics are only calculated when appropriate for the statistic. Certain statistics require tables of a particular size, and some statistics are calculated only in integer mode.
/STATISTICS without any settings selects CHISQ. If the STATISTICS subcommand is not given, no statistics are calculated.
Please note: Currently the implementation of CROSSTABS has the followings bugs:
Fixes for any of these deficiencies would be welcomed.
T-TEST
/MISSING={ANALYSIS,LISTWISE} {EXCLUDE,INCLUDE}
/CRITERIA=CIN(confidence)
(One Sample mode.)
TESTVAL=test_value
/VARIABLES=var_list
(Independent Samples mode.)
GROUPS=var(value1 [, value2])
/VARIABLES=var_list
(Paired Samples mode.)
PAIRS=var_list [WITH var_list [(PAIRED)] ]
The T-TEST procedure outputs tables used in testing hypotheses about means. It operates in one of three modes:
Each of these modes are described in more detail below. There are two optional subcommands which are common to all modes.
The /CRITERIA subcommand tells PSPP the confidence interval used in the tests. The default value is 0.95.
The MISSING subcommand determines the handling of missing variables. If INCLUDE is set, then user-missing values are included in the calculations, but system-missing values are not. If EXCLUDE is set, which is the default, user-missing values are excluded as well as system-missing values. This is the default.
If LISTWISE is set, then the entire case is excluded from analysis whenever any variable specified in the /VARIABLES, /PAIRS or /GROUPS subcommands contains a missing value. If ANALYSIS is set, then missing values are excluded only in the analysis for which they would be needed. This is the default.
The TESTVAL subcommand invokes the One Sample mode. This mode is used to test a population mean against a hypothesised mean. The value given to the TESTVAL subcommand is the value against which you wish to test. In this mode, you must also use the /VARIABLES subcommand to tell PSPP which variables you wish to test.
The GROUPS subcommand invokes Independent Samples mode or `Groups' mode. This mode is used to test whether two groups of values have the same population mean. In this mode, you must also use the /VARIABLES subcommand to tell PSPP the dependent variables you wish to test.
The variable given in the GROUPS subcommand is the independent variable which determines to which group the samples belong. The values in parentheses are the specific values of the independent variable for each group. If the parentheses are omitted and no values are given, the default values of 1.0 and 2.0 are assumed.
If the independent variable is numeric, it is acceptable to specify only one value inside the parentheses. If you do this, cases where the independent variable is less than or equal to this value belong to the first group, and cases greater than this value belong to the second group. When using this form of the GROUPS subcommand, missing values in the independent variable are excluded on a listwise basis, regardless of whether /MISSING=LISTWISE was specified.
The PAIRS subcommand introduces Paired Samples mode.
Use this mode when repeated measures have been taken from the same
samples.
If the the WITH keyword is omitted, then tables for all
combinations of variables given in the PAIRS subcommand are
generated.
If the WITH keyword is given, and the (PAIRED) keyword
is also given, then the number of variables preceding WITH
must be the same as the number following it.
In this case, tables for each respective pair of variables are
generated.
In the event that the WITH keyword is given, but the
(PAIRED) keyword is omitted, then tables for each combination
of variable preceding WITH against variable following
WITH are generated.
ONEWAY
[/VARIABLES = ] var_list BY var
/MISSING={ANALYSIS,LISTWISE} {EXCLUDE,INCLUDE}
/CONTRASTS= value1 [, value2] ... [,valueN]
/STATISTICS={DESCRIPTIVES,HOMOGENEITY}
The ONEWAY procedure performs a one-way analysis of variance of variables factored by a single independent variable. It is used to compare the means of a population divided into more than two groups.
The variables to be analysed should be given in the VARIABLES
subcommand.
The list of variables must be followed by the BY keyword and
the name of the independent (or factor) variable.
You can use the STATISTICS subcommand to tell PSPP to display
ancilliary information. The options accepted are:
The CONTRASTS subcommand is used when you anticipate certain
differences between the groups.
The subcommand must be followed by a list of numerals which are the
coefficients of the groups to be tested.
The number of coefficients must correspond to the number of distinct
groups (or values of the independent variable).
If the total sum of the coefficients are not zero, then PSPP will
display a warning, but will proceed with the analysis.
The CONTRASTS subcommand may be given up to 10 times in order
to specify different contrast tests.
Commands that don't fit any other category are placed here.
Most of these commands are not affected by commands like IF and LOOP: they take effect only once, unconditionally, at the time that they are encountered in the input.
Two possibles syntaxes:
COMMENT comment text ... .
*comment text ... .
COMMENT is ignored. It is used to provide information to the author and other readers of the PSPP syntax file.
COMMENT can extend over any number of lines. Don't forget to terminate it with a dot or a blank line.
DOCUMENT documentary_text.
DOCUMENT adds one or more lines of descriptive commentary to the active file. Documents added in this way are saved to system files. They can be viewed using SYSFILE INFO or DISPLAY DOCUMENTS. They can be removed from the active file with DROP DOCUMENTS.
Specify the documentary text following the DOCUMENT keyword. You can extend the documentary text over as many lines as necessary. Lines are truncated at 80 characters width. Don't forget to terminate the command with a dot or a blank line.
DISPLAY DOCUMENTS.
DISPLAY DOCUMENTS displays the documents in the active file. Each document is preceded by a line giving the time and date that it was added. See DOCUMENT.
DISPLAY FILE LABEL.
DISPLAY FILE LABEL displays the file label contained in the active file, if any. See FILE LABEL.
DROP DOCUMENTS.
DROP DOCUMENTS removes all documents from the active file. New documents can be added with DOCUMENT (see DOCUMENT).
DROP DOCUMENTS changes only the active file. It does not modify any system files stored on disk.
ECHO 'arbitrary text' .
Use ECHO to write arbitrary text to the output stream. The text should be enclosed in quotation marks following the normal rules for string tokens (see Tokens).
ERASE FILE file_name.
ERASE FILE deletes a file from the local filesystem. file_name must be quoted. This command cannot be used if the SAFER setting is active.
EXECUTE.
EXECUTE causes the active file to be read and all pending transformations to be executed.
FILE LABEL file_label.
FILE LABEL provides a title for the active file. This title will be saved into system files and portable files that are created during this PSPP run.
file_label need not be quoted. If quotes are included, they become part of the file label.
FINISH.
FINISH terminates the current PSPP session and returns control to the operating system.
This command is not valid in interactive mode.
HOST.
HOST suspends the current PSPP session and temporarily returns control to the operating system. This command cannot be used if the SAFER setting is active.
Two possible syntaxes:
INCLUDE 'filename'.
@filename.
INCLUDE causes the PSPP command processor to read an additional command file as if it were included bodily in the current command file.
Include files may be nested to any depth, up to the limit of available memory.
PERMISSIONS
FILE='filename'
/PERMISSIONS = {READONLY,WRITEABLE}.
PERMISSIONS changes the permissions of a file. There is one mandatory subcommand which specifies the permissions to which the file should be changed. If you set a file's permission to READONLY, then the file will become unwritable either by you or anyone else on the system. If you set the permission to WRITEABLE, then the file will become writeable by you; the permissions afforded to others will be unchanged. This command cannot be used if the SAFER setting is active.
Two possible syntaxes:
QUIT.
EXIT.
QUIT terminates the current PSPP session and returns control to the operating system.
This command is not valid within a command file.
SET
(data input)
/BLANKS={SYSMIS,'.',number}
/DECIMAL={DOT,COMMA}
/FORMAT=fmt_spec
/EPOCH={AUTOMATIC,year}
(program input)
/ENDCMD='.'
/NULLINE={ON,OFF}
(interaction)
/CPROMPT='cprompt_string'
/DPROMPT='dprompt_string'
/ERRORBREAK={OFF,ON}
/MXERRS=max_errs
/MXWARNS=max_warnings
/PROMPT='prompt'
/VIEWLENGTH={MINIMUM,MEDIAN,MAXIMUM,n_lines}
/VIEWWIDTH=n_characters
(program execution)
/MEXPAND={ON,OFF}
/MITERATE=max_iterations
/MNEST=max_nest
/MPRINT={ON,OFF}
/MXLOOPS=max_loops
/SEED={RANDOM,seed_value}
/UNDEFINED={WARN,NOWARN}
(data output)
/CC{A,B,C,D,E}={'npre,pre,suf,nsuf','npre.pre.suf.nsuf'}
/DECIMAL={DOT,COMMA}
/FORMAT=fmt_spec
(output routing)
/ECHO={ON,OFF}
/ERRORS={ON,OFF,TERMINAL,LISTING,BOTH,NONE}
/INCLUDE={ON,OFF}
/MESSAGES={ON,OFF,TERMINAL,LISTING,BOTH,NONE}
/PRINTBACK={ON,OFF}
/RESULTS={ON,OFF,TERMINAL,LISTING,BOTH,NONE}
(output activation)
/LISTING={ON,OFF}
/PRINTER={ON,OFF}
/SCREEN={ON,OFF}
(output driver options)
/HEADERS={NO,YES,BLANK}
/LENGTH={NONE,length_in_lines}
/LISTING=filename
/MORE={ON,OFF}
/PAGER={OFF,"pager_name"}
/WIDTH={NARROW,WIDTH,n_characters}
(logging)
/JOURNAL={ON,OFF} [filename]
/LOG={ON,OFF} [filename]
(system files)
/COMPRESSION={ON,OFF}
/SCOMPRESSION={ON,OFF}
(security)
/SAFER=ON
(obsolete settings accepted for compatibility, but ignored)
/AUTOMENU={ON,OFF}
/BEEP={ON,OFF}
/BLOCK='c'
/BOXSTRING={'xxx','xxxxxxxxxxx'}
/CASE={UPPER,UPLOW}
/COLOR=...
/CPI=cpi_value
/DISK={ON,OFF}
/EJECT={ON,OFF}
/HELPWINDOWS={ON,OFF}
/HIGHRES={ON,OFF}
/HISTOGRAM='c'
/LOWRES={AUTO,ON,OFF}
/LPI=lpi_value
/MENUS={STANDARD,EXTENDED}
/MXMEMORY=max_memory
/PTRANSLATE={ON,OFF}
/RCOLORS=...
/RUNREVIEW={AUTO,MANUAL}
/SCRIPTTAB='c'
/TB1={'xxx','xxxxxxxxxxx'}
/TBFONTS='string'
/WORKDEV=drive_letter
/WORKSPACE=workspace_size
/XSORT={YES,NO}
SET allows the user to adjust several parameters relating to PSPP's execution. Since there are many subcommands to this command, its subcommands will be examined in groups.
On subcommands that take boolean values, ON and YES are synonym, and as are OFF and NO, when used as subcommand values.
The data input subcommands affect the way that data is read from data files. The data input subcommands are
Program input subcommands affect the way that programs are parsed when they are typed interactively or run from a script. They are
Interaction subcommands affect the way that PSPP interacts with an online user. The interaction subcommands are
Program execution subcommands control the way that PSPP commands execute. The program execution subcommands are
Data output subcommands affect the format of output data. These subcommands are
The commas or periods divide the string into four fields, which are, in
order, the negative prefix, prefix, suffix, and negative suffix. When a
value is formatted using the custom currency format, the prefix precedes
the value formatted and the suffix follows it. In addition, if the
value is negative, the negative prefix precedes the prefix and the
negative suffix follows the suffix.
Output routing subcommands affect where the output of transformations and procedures is sent. These subcommands are
Output activation subcommands affect whether output devices of particular types are enabled. These subcommands are
Output driver option subcommands affect output drivers' settings. These subcommands are
Logging subcommands affect logging of commands executed to external files. These subcommands are
System file subcommands affect the default format of system files produced by PSPP. These subcommands are
Security subcommands affect the operations that commands are allowed to perform. The security subcommands are
Be aware that this setting does not guarantee safety (commands can still overwrite files, for instance) but it is an improvement. When set, this setting cannot be reset during the same session, for obvious security reasons.
SHOW
/subcommand
SHOW can be used to display the current state of PSPP's
execution parameters. All of the parameters which can be changed
using SET See SET, can be examined using SHOW, by
using a subcommand with the same name.
In addition, SHOW supports the following subcommands:
WARRANTYCOPYING SUBTITLE 'subtitle_string'.
or
SUBTITLE subtitle_string.
SUBTITLE provides a subtitle to a particular PSPP run. This subtitle appears at the top of each output page below the title, if headers are enabled on the output device.
Specify a subtitle as a string in quotes. The alternate syntax that did not require quotes is now obsolete. If it is used then the subtitle is converted to all uppercase.
TITLE 'title_string'.
or
TITLE title_string.
TITLE provides a title to a particular PSPP run. This title appears at the top of each output page, if headers are enabled on the output device.
Specify a title as a string in quotes. The alternate syntax that did not require quotes is now obsolete. If it is used then the title is converted to all uppercase.
This chapter lists parts of the PSPP language that are not yet implemented.
PSPP does have bugs. We do our best to fix them, but our limited resources mean that some may remain for a long time. Our best alternative is to make you aware of PSPP's known bugs. To see a list, visit PSPP's project webpage at https://savannah.gnu.org/projects/pspp. You can also submit your own bug report there: click on “Bugs,” then on “Submit a Bug,” and fill out the form. Alternatively, PSPP bug reports may be sent by email to
For known bugs in individual language features, see the documentation for that feature.
ABS: Miscellaneous MathematicsACOS: TrigonometryANY: Set MembershipARCOS: TrigonometryARSIN: TrigonometryARTAN: TrigonometryASIN: TrigonometryATAN: TrigonometryCDF.BERNOULLI: Discrete DistributionsCDF.BETA: Continuous DistributionsCDF.BINOMIAL: Discrete DistributionsCDF.CAUCHY: Continuous DistributionsCDF.CHISQ: Continuous DistributionsCDF.EXP: Continuous DistributionsCDF.F: Continuous DistributionsCDF.GAMMA: Continuous DistributionsCDF.GEOM: Discrete DistributionsCDF.HALFNRM: Continuous DistributionsCDF.HYPER: Discrete DistributionsCDF.IGAUSS: Continuous DistributionsCDF.LAPLACE: Continuous DistributionsCDF.LNORMAL: Continuous DistributionsCDF.LOGISTIC: Continuous DistributionsCDF.NEGBIN: Discrete DistributionsCDF.NORMAL: Continuous DistributionsCDF.PARETO: Continuous DistributionsCDF.POISSON: Discrete DistributionsCDF.RAYLEIGH: Continuous DistributionsCDF.SMOD: Continuous DistributionsCDF.SRANGE: Continuous DistributionsCDF.T: Continuous DistributionsCDF.T1G: Continuous DistributionsCDF.T2G: Continuous DistributionsCDF.UNIFORM: Continuous DistributionsCDF.VBNOR: Continuous DistributionsCDF.WEIBULL: Continuous DistributionsCDFNORM: Continuous DistributionsCFVAR: Statistical FunctionsCONCAT: String FunctionsCOS: TrigonometryCTIME.DAYS: Time ExtractionCTIME.HOURS: Time ExtractionCTIME.MINUTES: Time ExtractionCTIME.SECONDS: Time ExtractionDATE.DMY: Date ConstructionDATE.MDY: Date ConstructionDATE.MOYR: Date ConstructionDATE.QYR: Date ConstructionDATE.WKYR: Date ConstructionDATE.YRDAY: Date ConstructionEXP: MathematicsIDF.BETA: Continuous DistributionsIDF.CAUCHY: Continuous DistributionsIDF.CHISQ: Continuous DistributionsIDF.EXP: Continuous DistributionsIDF.F: Continuous DistributionsIDF.GAMMA: Continuous DistributionsIDF.HALFNRM: Continuous DistributionsIDF.IGAUSS: Continuous DistributionsIDF.LAPLACE: Continuous DistributionsIDF.LNORMAL: Continuous DistributionsIDF.LOGISTIC: Continuous DistributionsIDF.NORMAL: Continuous DistributionsIDF.PARETO: Continuous DistributionsIDF.RAYLEIGH: Continuous DistributionsIDF.SMOD: Continuous DistributionsIDF.SRANGE: Continuous DistributionsIDF.T: Continuous DistributionsIDF.T1G: Continuous DistributionsIDF.T2G: Continuous DistributionsIDF.UNIFORM: Continuous DistributionsIDF.WEIBULL: Continuous DistributionsINDEX: String FunctionsLAG: Miscellaneous FunctionsLENGTH: String FunctionsLG10: MathematicsLN: MathematicsLNGAMMA: MathematicsLOWER: String FunctionsLPAD: String FunctionsLTRIM: String FunctionsMAX: Statistical FunctionsMEAN: Statistical FunctionsMIN: Statistical FunctionsMISSING: Missing Value FunctionsMOD: Miscellaneous MathematicsMOD10: Miscellaneous MathematicsNCDF.BETA: Continuous DistributionsNCDF.CHISQ: Continuous DistributionsNCDF.F: Continuous DistributionsNCDF.T: Continuous DistributionsNMISS: Missing Value FunctionsNORMAL: Continuous DistributionsNPDF.BETA: Continuous DistributionsNPDF.CHISQ: Continuous DistributionsNPDF.F: Continuous DistributionsNPDF.T: Continuous DistributionsNUMBER: String FunctionsNVALID: Missing Value FunctionsPDF.BERNOULLI: Discrete DistributionsPDF.BETA: Continuous DistributionsPDF.BINOMIAL: Discrete DistributionsPDF.BVNOR: Continuous DistributionsPDF.CAUCHY: Continuous DistributionsPDF.CHISQ: Continuous DistributionsPDF.EXP: Continuous DistributionsPDF.F: Continuous DistributionsPDF.GAMMA: Continuous DistributionsPDF.GEOM: Discrete DistributionsPDF.HALFNRM: Continuous DistributionsPDF.HYPER: Discrete DistributionsPDF.IGAUSS: Continuous DistributionsPDF.LANDAU: Continuous DistributionsPDF.LAPLACE: Continuous DistributionsPDF.LNORMAL: Continuous DistributionsPDF.LOG: Discrete DistributionsPDF.LOGISTIC: Continuous DistributionsPDF.NEGBIN: Discrete DistributionsPDF.NORMAL: Continuous DistributionsPDF.NTAIL: Continuous DistributionsPDF.PARETO: Continuous DistributionsPDF.POISSON: Discrete DistributionsPDF.RAYLEIGH: Continuous DistributionsPDF.RTAIL: Continuous DistributionsPDF.T: Continuous DistributionsPDF.T1G: Continuous DistributionsPDF.T2G: Continuous DistributionsPDF.UNIFORM: Continuous DistributionsPDF.WEIBULL: Continuous DistributionsPDF.XPOWER: Continuous DistributionsPROBIT: Continuous DistributionsRANGE: Set MembershipRINDEX: String FunctionsRND: Miscellaneous MathematicsRPAD: String FunctionsRTRIM: String FunctionsRV.BERNOULLI: Discrete DistributionsRV.BETA: Continuous DistributionsRV.BINOMIAL: Discrete DistributionsRV.CAUCHY: Continuous DistributionsRV.CHISQ: Continuous DistributionsRV.EXP: Continuous DistributionsRV.F: Continuous DistributionsRV.GAMMA: Continuous DistributionsRV.GEOM: Discrete DistributionsRV.HALFNRM: Continuous DistributionsRV.HYPER: Discrete DistributionsRV.IGAUSS: Continuous DistributionsRV.LANDAU: Continuous DistributionsRV.LAPLACE: Continuous DistributionsRV.LEVY: Continuous DistributionsRV.LNORMAL: Continuous DistributionsRV.LOG: Discrete DistributionsRV.LOGISTIC: Continuous DistributionsRV.LVSKEW: Continuous DistributionsRV.NEGBIN: Discrete DistributionsRV.NORMAL: Continuous DistributionsRV.NTAIL: Continuous DistributionsRV.PARETO: Continuous DistributionsRV.POISSON: Discrete DistributionsRV.RAYLEIGH: Continuous DistributionsRV.RTAIL: Continuous DistributionsRV.T: Continuous DistributionsRV.UNIFORM: Continuous DistributionsRV.WEIBULL: Continuous DistributionsRV.XPOWER: Continuous DistributionsSD: Statistical FunctionsSIG.CHISQ: Continuous DistributionsSIG.F: Continuous DistributionsSIN: TrigonometrySQRT: MathematicsSTRING: String FunctionsSUBSTR: String FunctionsSUM: Statistical FunctionsSYSMIS: Missing Value FunctionsTAN: TrigonometryTIME.DAYS: Time ConstructionTIME.HMS: Time ConstructionTRUNC: Miscellaneous MathematicsUNIFORM: Continuous DistributionsUPCASE: String FunctionsVALUE: Missing Value FunctionsVARIANCE: Statistical FunctionsXDATE.DATE: Date ExtractionXDATE.HOUR: Date ExtractionXDATE.JDAY: Date ExtractionXDATE.MDAY: Date ExtractionXDATE.MINUTE: Date ExtractionXDATE.MONTH: Date ExtractionXDATE.QUARTER: Date ExtractionXDATE.SECOND: Date ExtractionXDATE.TDAY: Date ExtractionXDATE.TIME: Date ExtractionXDATE.WEEK: Date ExtractionXDATE.WKDAY: Date ExtractionXDATE.YEAR: Date ExtractionYRMODA: Miscellaneous Functions*: COMMENT@: INCLUDEADD VALUE LABELS: ADD VALUE LABELSAGGREGATE: AGGREGATEAPPLY DICTIONARY: APPLY DICTIONARYAUTORECODE: AUTORECODEBEGIN DATA: BEGIN DATABREAK: BREAKCLEAR TRANSFORMATIONS: CLEAR TRANSFORMATIONSCOMMENT: COMMENTCOMPUTE: COMPUTECOUNT: COUNTCROSSTABS: CROSSTABSDATA LIST: DATA LISTDATA LIST FIXED: DATA LIST FIXEDDATA LIST FREE: DATA LIST FREEDATA LIST LIST: DATA LIST LISTDESCRIPTIVES: DESCRIPTIVESDISPLAY: DISPLAYDISPLAY DOCUMENTS: DISPLAY DOCUMENTSDISPLAY FILE LABEL: DISPLAY FILE LABELDISPLAY VECTORS: DISPLAY VECTORSDO IF: DO IFDO REPEAT: DO REPEATDOCUMENT: DOCUMENTDROP DOCUMENTS: DROP DOCUMENTSECHO: ECHOEND CASE: END CASEEND DATA: BEGIN DATAEND FILE: END FILEERASE: ERASEEXAMINE: EXAMINEEXECUTE: EXECUTEEXPORT: EXPORTFILE HANDLE: FILE HANDLEFILE LABEL: FILE LABELFILTER: FILTERFINISH: FINISHFLIP: FLIPFORMATS: FORMATSFREQUENCIES: FREQUENCIESGET: GETHOST: HOSTIF: IFIMPORT: IMPORTINCLUDE: INCLUDEINPUT PROGRAM: INPUT PROGRAMLEAVE: LEAVELIST: LISTLOOP: LOOPMATCH FILES: MATCH FILESMATRIX DATA: MATRIX DATAMISSING VALUES: MISSING VALUESMODIFY VARS: MODIFY VARSN OF CASES: N OF CASESNEW FILE: NEW FILENUMERIC: NUMERICONEWAY: ONEWAYPERMISSIONS: PERMISSIONSPRINT: PRINTPRINT EJECT: PRINT EJECTPRINT FORMATS: PRINT FORMATSPRINT SPACE: PRINT SPACEPROCESS IF: PROCESS IFQUIT: QUITRECODE: RECODERENAME VARIABLES: RENAME VARIABLESREPEATING DATA: REPEATING DATAREREAD: REREADSAMPLE: SAMPLESAVE: SAVESELECT IF: SELECT IFSET: SETSHOW: SHOWSORT CASES: SORT CASESSPLIT FILE: SPLIT FILESTRING: STRINGSUBTITLE: SUBTITLESYSFILE INFO: SYSFILE INFOT-TEST: T-TESTTEMPORARY: TEMPORARYTITLE: TITLEVALUE LABELS: VALUE LABELSVARIABLE ALIGNMENT: VARIABLE ALIGNMENTVARIABLE LABELS: VARIABLE LABELSVARIABLE LEVEL: VARIABLE LEVELVARIABLE WIDTH: VARIABLE WIDTHVECTOR: VECTORWEIGHT: WEIGHTWRITE: WRITEWRITE FORMATS: WRITE FORMATSXSAVE: XSAVE$CASENUM: System Variables$DATE: System Variables$JDATE: System Variables$LENGTH: System Variables$SYSMIS: System Variables$TIME: System Variables$WIDTH: System Variables(: Functions): Functions.: BNF<: Relational Operators<=: Relational Operators<>: Relational Operators>=: Relational OperatorsAND: Logical OperatorsEQ: Relational Operatorsexpression: BNFGE: Relational OperatorsGT: Relational Operatorsinteger: BNFLE: Relational OperatorsLT: Relational OperatorsNE: Relational OperatorsNOT: Logical Operatorsnumber: BNFOR: Logical Operatorsstring: BNFvar-list: BNFvar-name: BNF~=: Relational OperatorsPSPP conforms to the GNU Coding Standards. PSPP is written in, and requires for proper operation, ANSI/ISO C. You might want to additionally note the following points:
int type must be 32 bits or wider.
Many UNIX variants should work out-of-the-box, as PSPP uses GNU autoconf to detect differences between environments. Please report any problems with compilation of PSPP under UNIX and UNIX-like operating systems—portability is a major concern of the author.
The pages below give specific instructions for installing PSPP on each type of system mentioned above.
To install PSPP under a UNIX-like operating system, follow the steps below in order. Some of the text below was taken directly from various Free Software Foundation sources.
cd to the directory containing the PSPP source.
configure takes a while. While
running, it displays some messages telling which features it is checking
for.
You can optionally supply some options to configure to
give it hints about how to do its job. Type ./configure --help
to see a list of options. One of the most useful options is
--with-checker, which enables the use of the Checker memory
debugger under supported operating systems. Checker must already be
installed to use this option. Do not use --with-checker if you
are not debugging PSPP itself.
configure. Note that most PSPP
settings can be changed at runtime.
pref.h is only generated by configure if it does not
already exist. (It's copied from prefh.orig.)
PSPP has dozens of configuration possibilities and hundreds of settings. This is both a bane and a blessing. On one hand, it's possible to easily accommodate diverse ranges of setups. But, on the other, the multitude of possibilities can overwhelm the casual user. Fortunately, the configuration mechanisms are profusely described in the sections below....
PSPP uses the same method to find most of its configuration files:
The first two steps are elaborated below for the sake of our pedantic friends.
Determining the base name is a two-step process:
STAT_OUTPUT_INIT_FILE.
Please note: If a user-specified base name does contain an absolute directory reference, as in a file name like /home/pfaff/fonts/TR, no path is searched—the file name is used exactly as given—and the algorithm terminates.
STAT_OUTPUT_INIT_PATH.
STAT_GROFF_FONT_PATH, then for
one with name GROFF_FONT_PATH. (However, font searching has its
own list of esoteric search rules.)
STAT_CONFIG_PATH is
defined, the value of that variable is used.
On DOS machines, the default fallback path is:
Note that the installer of PSPP can easily change this default fallback path; thus the above should not be taken as gospel.
As a final note: Under DOS, directories given in paths are delimited by semicolons (;); under UNIX, directories are delimited by colons (:). This corresponds with the standard path delimiter under these OSes.
There are many ways that PSPP can be configured. These are described in the list below. Values given by earlier items take precedence over those given by later items.
Some of the above may not apply to a particular setting. For instance, the current pager (such as more, most, or less) cannot be determined by configuration file contents because there is no appropriate configuration file.
Most configuration files have a common form:
(This is distinct from the use of a backslash as a line-splicing character.)
You may think the concept of environment variables is a fairly simple one. However, the author of PSPP has found a way to complicate even something so simple. Environment variables are further described in the sections below:
Values for environment variables are obtained by the following means, which are arranged in order of decreasing precedence:
The environment configuration file is located through application of the usual algorithm for configuration files (see File locations), except that its contents do not affect the search path used to find environment itself. Use of environment is discouraged on systems that allow an arbitrarily large environment; it is supported for use on systems like MS-DOS that limit environment size.
environment is composed of lines having the form key=value, where key and the equals sign (=) are required, and value is optional. If value is given, variable key is given that value; if value is absent, variable key is undefined (deleted). Variables may not be defined with a null value.
Environment substitutions are performed on each line in the file (see Environment substitutions).
See Configuration files, for more details on formatting of the environment configuration file.
Please note: Support for environment is not yet implemented.
Much of the power of environment variables lies in the way that they may be substituted into configuration files. Variable substitutions are described below.
The line is scanned from left to right. In this scan, all characters other than dollar signs ($) are retained unmolested. Dollar signs, however, introduce an environment variable reference. References take three forms:
$var${var}$$Undefined variables expand to a empty value.
There are two environment variables predefined for use in environment substitutions:
Nothing prevents these values from being overridden, although it's a good idea not to do so.
Configuring output devices is the most complicated aspect of configuring PSPP. The output device configuration file is named devices. It is searched for using the usual algorithm for finding configuration files (see File locations). Each line in the file is read in the usual manner for configuration files (see Configuration files).
Lines in devices are divided into three categories, described briefly in the table below:
The following sections further elaborate the contents of the devices file.
Drivers can be divided into categories. Drivers are specified by their names, or by the names of the categories that they are contained in. Only certain drivers are enabled each time PSPP is run; by default, these are the drivers in the category `default'. To enable a different set of drivers, use the -o device command-line option (see Invocation).
Categories are specified with a line of the form category=driver1 driver2 driver3 ... drivern. This line specifies that the category category is composed of drivers named driver1, driver2, and so on. There may be any number of drivers in the category, from zero on up.
Categories may also be specified on the command line (see Invocation).
This is all you need to know about categories. If you're still curious, read on.
First of all, the term `categories' is a bit of a misnomer. In fact, the internal representation is nothing like the hierarchy that the term seems to imply: a linear list is used to keep track of the enabled drivers.
When PSPP first begins reading devices, this list contains the name of any drivers or categories specified on the command line, or the single item `default' if none were specified.
Each time a category definition is specified, the list is searched for an item with the value of category. If a matching item is found, it is deleted. If there was a match, the list of drivers (driver1 through drivern) is then appended to the list.
Each time a driver definition line is encountered, the list is searched. If the list contains an item with that driver's name, the driver is enabled and the item is deleted from the list. Otherwise, the driver is not enabled.
It is an error if the list is not empty when the end of devices is reached.
Macro definitions take the form define macroname definition. In such a macro definition, the environment variable macroname is defined to expand to the value definition. Before the definition is made, however, any macros used in definition are expanded.
Please note the following nuances of macro usage:
Driver definitions are the ultimate purpose of the devices configuration file. These are where the real action is. Driver definitions tell PSPP where it should send its output.
Each driver definition line is divided into four fields. These fields are delimited by colons (:). Each line is subjected to environment variable interpolation before it is processed further (see Environment substitutions). From left to right, the four fields are, in brief:
screenprinterlistingThese options are just hints to PSPP and do not cause the output to be
directed to the screen, or to the printer, or to a listing file—those
must be set elsewhere in the options. They are used primarily to decide
which devices should be enabled at any given time. See SET, for more
information.
The driver is enabled if:
default.
For more information on driver names, see Driver categories.
The class name must be one of those supported by PSPP. The classes supported depend on the options with which PSPP was compiled. See later sections in this chapter for descriptions of the available driver classes.
Options are dependent on the driver. See the driver descriptions for details.
Quite often in configuration it is necessary to specify a length or a size. PSPP uses a common syntax for all such, calling them collectively by the name dimensions.
inin = 2.54 cm)
"in = 2.54 cm)
ptin = 72.27 pt)
pcpt = 1 pc)
bpin = 72 bp)
cmmmmm = 1 cm)
dddd = 1238 pt)
cccc = 12 dd)
spsp = 1 pt)
Output drivers usually deal with some sort of hardcopy media. This media is called paper by the drivers, though in reality it could be a transparency or film or thinly veiled sarcasm. To make it easier for you to deal with paper, PSPP allows you to have (of course!) a configuration file that gives symbolic names, like “letter” or “legal” or “a4”, to paper sizes, rather than forcing you to use cryptic numbers like “8-1/2 x 11” or “210 by 297”. Surprisingly enough, this configuration file is named papersize. See Configuration files.
When PSPP tries to connect a symbolic paper name to a paper size, it reads and parses each non-comment line in the file, in order. The first field on each line must be a symbolic paper name in double quotes. Paper names may not contain double quotes. Paper names are not case-sensitive: legal and Legal are equivalent.
If a match is found for the paper name, the rest of the line is parsed. If it is found to be a pair of dimensions (see Dimensions) separated by either x or by, then those are taken to be the paper size, in order of width followed by length. There must be at least one space on each side of x or by.
Otherwise the line must be of the form "paper-1"="paper-2". In this case the target of the search becomes paper name paper-2 and the search through the file continues.
The lines in devices are distinguished in the following manner:
define,
followed by one or more white space characters, the line is processed as
a macro definition.
Each driver definition line is run through a simple tokenizer. This tokenizer recognizes two basic types of tokens.
The first type is an equals sign (=). Equals signs are both delimiters between tokens and tokens in themselves.
The second type is an identifier or string token. Identifiers and strings are equivalent after tokenization, though they are written differently. An identifier is any string of characters other than white space or equals sign.
A string is introduced by a single- or double-quote character (' or ") and, in general, continues until the next occurrence of that same character. The following standard C escapes can also be embedded within strings:
\'\"\?\\\a\b\f\n\r\t\v\ooo\xhhTokens, outside of quoted strings, are delimited by white space or equals signs.
The postscript driver class is used to produce output that is
acceptable to PostScript printers and to PC-based PostScript
interpreters such as Ghostscript. Continuing a long tradition,
PSPP's PostScript driver is configurable to the point of
absurdity.
There are actually two PostScript drivers. The first one, postscript, produces ordinary DSC-compliant PostScript output. The second one epsf, produces an Encapsulated PostScript file. The two drivers are otherwise identical in configuration and in operation.
The PostScript driver is described in further detail below.
These options deal with the form of the output and the output file itself:
output-file=filename"pspp.ps"), a pipe filename (i.e., "|lpr"), or
stdout ("-"). Default: "pspp.ps".
color=booleancolor off. Default: on.
This is a boolean setting, as are many settings in the PostScript
driver. Valid positive boolean values are on, true,
yes, and nonzero integers. Negative boolean values are
off, false, no, and zero.
data=data-typeclean7bit, clean8bit, or binary. This
controls what characters will be written to the output file. PostScript
produced with clean7bit can be transmitted over 7-bit
transmission channels that use ASCII control characters for line
control. clean8bit is similar but allows characters above 127 to
be written to the output file. binary allows any character in
the output file. Default: clean7bit.
line-ends=line-end-typecr, lf, or crlf. This controls what is used
for new-line in the output file. Default: cr.
optimize-line-size=level0 or 1. If level is 1, then short
line segments will be collected and merged into longer ones. This
reduces output file size but requires more time and memory. A
level of 0 has the advantage of being better for
interactive environments. 1 is the default unless the
screen flag is set; in that case, the default is 0.
optimize-text-size=level0, 1, or 2, each higher level representing
correspondingly more aggressive space savings for text in the output
file and requiring correspondingly more time and memory. Unfortunately
the levels presently are all the same. 1 is the default unless
the screen flag is set; in that case, the default is 0.
These options affect page setup:
headers=booleanon.
paper-size=paper-sizeletter or a4)
or specific measurements (i.e., 8-1/2x11 or "210 x 297".
See Paper sizes. Default: letter.
orientation=orientationportrait or landscape. Default: portrait.
left-margin=dimensionright-margin=dimensiontop-margin=dimensionbottom-margin=dimension0.5in.
Oh, my. You don't really want to know about the way that the PostScript driver deals with files, do you? Well I suppose you're entitled, but I warn you right now: it's not pretty. Here goes....
First let's look at the options that are available:
font-dir=font-directorydevps.
prologue-file=prologue-file-nameps-prologue.
device-file=device-file-nameDESC.
encoding-file=encoding-file-nameps-encodings.
If the specified encoding file cannot be found, this error will be
silently ignored, since most people do not need any encodings besides
the ones that can be found using auto-encodings, described below.
auto-encode=booleanon.
Next I suppose it's time to describe the search algorithm. When the PostScript driver needs a file, whether that file be a font, a PostScript prologue, or what you will, it searches in this manner:
STAT_GROFF_FONT_PATH. See Environment variables.
GROFF_FONT_PATH.
devps/ps-encodings.
ps-encodings.
So, as you see, there are several ways to configure the PostScript drivers. Careful selection of techniques can make the configuration very flexible indeed.
The list of available font options is short and sweet:
prop-font=font-name"Helvetica".
fixed-font=font-name"Courier".
font-size=font-size10000.
Most tables contain lines, or rules, between cells. Some features of the way that lines are drawn in PostScript tables are user-definable:
line-style=stylethick, in which case thick lines are
used, or double, in which case double lines are used. Default:
thick.
line-gutter=dimension0.5pt.
line-spacing=dimension0.5pt.
line-width=dimension0.5pt.
line-width-thick=dimensionline-style is set to thick. Default: 1.5pt.
Most PostScript files that are generated mechanically by programs consist of two parts: a prologue and a body. The prologue is generally a collection of boilerplate. Only the body differs greatly between two outputs from the same program.
This is also the strategy used in the PSPP PostScript driver. In general, the prologue supplied with PSPP will be more than sufficient. In this case, you will not need to read the rest of this section. However, hackers might want to know more. Read on, if you fall into this category.
The prologue is dumped into the output stream essentially unmodified. However, two actions are performed on its lines. First, certain lines may be omitted as specified in the prologue file itself. Second, variables are substituted.
The following lines are omitted:
!!!).
!eps, if the PostScript driver is producing
ordinary PostScript output. Otherwise an EPS file is being produced,
and the line is included in the output, although everything following
!eps is deleted.
!ps, if the PostScript driver is producing EPS
output. Otherwise, ordinary PostScript is being produced, and the line
is included in the output, although everything following !ps is
deleted.
The following are the variables that are substituted. Only the variables listed are substituted; environment variables are not. See Environment substitutions.
bounding-boxcreatordatedatadata PostScript driver option, as one of the strings
Clean7Bit, Clean8Bit, or Binary.
orientationPortrait or
Landscape.
userLOGNAME or, if that fails, the result of the
C library function getlogin(). Defaults to nobody.
hostgethostname(). Defaults to
nowhere.
prop-fontfixed-fontscale-factor1.0. Note that this is also passed as an argument to the BP
macro.
paper-lengthpaper-widthleft-margintop-margintitlesource-fileAny other questions about the PostScript prologue can best be answered by examining the default prologue or the PSPP source.
PostScript fonts often contain many more than 256 characters, in order to accommodate foreign language characters and special symbols. PostScript uses encodings to map these onto single-byte symbol sets. Each font can have many different encodings applied to it.
PSPP's PostScript driver needs to know which encoding to apply to each font. It can determine this from the information encapsulated in the Groff font description that it reads. However, there is an additional problem—for efficiency, the PostScript driver needs to have a complete list of all encodings that will be used in the entire session when it opens the output file. For this reason, it can't use the information built into the fonts because it doesn't know which fonts will be used.
As a stopgap solution, there are two mechanisms for specifying which encodings will be used. The first mechanism is automatic and it is the only one that most PSPP users will ever need. The second mechanism is manual, but it is more flexible. Either mechanism or both may be used at one time.
The first mechanism is activated by the auto-encode driver option (see PS file options). When enabled, auto-encode causes the PostScript driver to include the encodings used by the default proportional and fixed-pitch fonts (see PS font options). Many PSPP output files will only need these encodings.
The second mechanism is the file specified by the encoding-file option (see PS file options). If it exists, this file must consist of lines in PSPP configuration-file format (see Configuration files). Each line that is not a comment should name a PostScript encoding to include in the output.
It is not an error if an encoding is included more than once, by either mechanism. It will appear only once in the output. It is also not an error if an encoding is included in the output but never used. It is an error if an encoding is used but not included by one of these mechanisms. In this case, the built-in PostScript encoding ISOLatin1Encoding is substituted.
The ASCII driver class produces output that can be displayed on a terminal or output to printers. All of its options are highly configurable. The ASCII driver has class name ascii.
The ASCII driver is described in further detail below.
output-file=filename"pspp.txt"), a pipe filename (e.g., "|lpr"), or
stdout ("-"). Default: "pspp.list".
char-set=char-set-typeascii.
form-feed-string=form-feed-valuepaginate, described below, for a related setting. Default:
"\f".
newline-string=new-line-valuenewline-string=default, is to use the system-dependent new-line
sequence by opening the output file in text mode. This is usually the
right choice.
However, newline-string can be set to any string. When this is
done, the output file is opened in binary mode.
paginate=booleanform-feed-string, described above)
will be written to the device after every page. Default: on.
tab-width=tab-width-value8.
init=initialization-string."" (the empty string).
done=finalization-string."" (the empty string).
These options affect page setup:
headers=booleanon.
length=line-count66.
width=character-count130.
lpi=lines-per-inch6.
cpi=characters-per-inch10.
left-margin=left-margin-width0.
right-margin=right-margin-width0.
top-margin=top-margin-lines2.
bottom-margin=bottom-margin-lines2.
These are the ASCII font options:
box[line-type]=box-charsline-type must be a 4-digit number in base 4. The digits are in the order `right', `bottom', `left', `top'. The four possibilities for each digit are:
Examples:
box[0101]="|"box[2222]="#"box[1100]="\xda"Defaults:
box[0000]=" "
box[1000]="-"
box[0010]="-"
box[1010]="-"
box[0100]="|"
box[0001]="|"
box[0101]="|"
box[2000]="="
box[0020]="="
box[2020]="="
box[0200]="#"
box[0002]="#"
box[0202]="#"
box[3000]="="
box[0030]="="
box[3030]="="
box[0300]="#"
box[0003]="#"
box[0303]="#"
italic-on=italic-on-stringoverstrike, then the driver will simulate
underlining by overstriking with underscore characters (_) in the
manner described by overstrike-style and
carriage-return-style. Default: overstrike.
italic-off=italic-off-string"" (the empty string).
bold-on=bold-on-stringoverstrike, then the driver will simulated bold printing
by overstriking characters in the manner described by
overstrike-style and carriage-return-style. Default:
overstrike.
bold-off=bold-off-string"" (the empty string).
bold-italic-on=bold-italic-on-stringoverstrike, then the driver will simulate bold-italics by
overstriking twice, once with the character, a second time with an
underscore (_) character, in the manner described by
overstrike-style and carriage-return-style. Default:
overstrike.
bold-italic-off=bold-italic-off-string""
(the empty string).
overstrike-style=overstrike-optionsingle or line:
single is selected, then, to overstrike a line of text, the
output driver will output a character, backspace, overstrike, output a
character, backspace, overstrike, and so on along a line.
line is selected then the output driver will output an entire
line, then backspace or emit a carriage return (as indicated by
carriage-return-style), then overstrike the entire line at once.
single is recommended for use with ttys and programs that
understand overstriking in text files, such as the pager less.
single will also work with printer devices but results in rapid
back-and-forth motions of the printhead that can cause the printer to
physically overheat!
line is recommended for use with printer devices. Most programs
that understand overstriking in text files will not properly deal with
line mode.
Default: single.
carriage-return-style=carriage-return-typebs or cr. This option applies only when one or
more of the font commands is set to overstrike and, at the same
time, overstrike-style is set to line.
bs is selected then the driver will return to the beginning of
a line by emitting a sequence of backspace characters (ASCII 8).
cr is selected then the driver will return to the beginning of
a line by emitting a single carriage-return character (ASCII 13).
Although cr is preferred as being more compact, bs is more
general since some devices do not interpret carriage returns in the
desired manner. Default: bs.
The html driver class is used to produce output for viewing in
tables-capable web browsers such as Emacs' w3-mode. Its configuration
is very simple. Currently, the output has a very plain format. In the
future, further work may be done on improving the output appearance.
There are few options for use with the html driver class:
output-file=filename"pspp.ps"), a pipe filename (i.e., "|lpr"), or
stdout ("-"). Default: "pspp.html".
prologue-file=prologue-file-namehtml-prologue.
HTML files that are generated by PSPP consist of two parts: a prologue and a body. The prologue is a collection of boilerplate. Only the body differs greatly between two outputs. You can tune the colors and other attributes of the output by editing the prologue.
The prologue is dumped into the output stream essentially unmodified. However, two actions are performed on its lines. First, certain lines may be omitted as specified in the prologue file itself. Second, variables are substituted.
The following lines are omitted:
!!!).
!title, if no title is set for the output. If
a title is set, then the characters !title are removed before the
line is output.
!subtitle, if no subtitle is set for the
output. If a subtitle is set, then the characters !subtitle are
removed before the line is output.
The following are the variables that are substituted. Only the variables listed are substituted; environment variables are not. See Environment substitutions.
generatordateuserLOGNAME or, if that fails, the result of the
C library function getlogin(). Defaults to nobody.
hostgethostname(). Defaults to
nowhere.
titlesubtitlesource-fileThe following environment variables can be used to further configure PSPP:
HOMESTAT_INCLUDE_PATHSTAT_PAGERPAGERTERMtermcap or ncurses will use, if such
support was compiled into PSPP.
STAT_OUTPUT_INIT_FILEdevices.
STAT_OUTPUT_PAPERSIZE_FILEpapersize.
STAT_OUTPUT_INIT_PATHTMPDIRTEMPTMPWhen its drivers are set up properly, PSPP can produce output that looks very good indeed. The PostScript driver, suitably configured, can produce presentation-quality output. Here are a few guidelines for producing better-looking output, regardless of output driver. Your mileage may vary, of course, and everyone has different esthetic preferences.
init-string setting. Try to get 132 columns; 160
might be better, but you might find that print that tiny is difficult to
read.
Try to strike a balance between character size and page width.
These days, most computers use the same internal data formats for integer and floating-point data, if one ignores little differences like big- versus little-endian byte ordering. However, occasionally it is necessary to exchange data between systems with incompatible data formats. This is what portable files are designed to do.
Please note: Although all of the following information is correct, as far as the author has been able to ascertain, it is gleaned from examination of ASCII-formatted portable files only, so some of it may be incorrect in the general case.
Portable files are arranged as a series of lines of exactly 80 characters each. Each line is terminated by a carriage-return, line-feed sequence “new-lines”). New-lines are only used to avoid line length limits imposed by some OSes; they are not meaningful.
The file must be terminated with a Z character. In addition, if the final line in the file does not have exactly 80 characters, then it is padded on the right with Z characters. (The file contents may be in any character set; the file contains a description of its own character set, as explained in the next section. Therefore, the Z character is not necessarily an ASCII Z.)
For the rest of the description of the portable file format, new-lines and the trailing Zs will be ignored, as if they did not exist, because they are not an important part of understanding the file contents.
Every portable file consists of the following records, in sequence:
Most records are identified by a single-character tag code. The file header and version info record do not have a tag.
Other than these single-character codes, there are three types of fields in a portable file: floating-point, integer, and string. Floating-point fields have the following format:
Integer fields take a form identical to floating-point fields, but they may not contain a fraction.
String fields take the form of a integer field having value n, followed by exactly n characters, which are the string content.
Every portable file begins with a 464-byte header, consisting of a 200-byte collection of vanity splash strings, followed by a 256-byte character set translation table, followed by an 8-byte tag string.
The 200-byte segment is divided into five 40-byte sections, each of
which represents the string charset SPSS PORT FILE in a
different character set encoding, where charset is the name of
the character set used in the file, e.g. ASCII or
EBCDIC. Each string is padded on the right with spaces in its
respective character set.
It appears that these strings exist only to inform those who might view the file on a screen, and that they are not parsed by SPSS products. Thus, they can be safely ignored. For those interested, the strings are supposed to be in the following character sets, in the specified order: EBCDIC, 7-bit ASCII, CDC 6-bit ASCII, 6-bit ASCII, Honeywell 6-bit ASCII.
The 256-byte segment describes a mapping from the character set used in the portable file to an arbitrary character set having characters at the following positions:
.<(+
&[]!$*);^-/
,%_>?`:
@'=".
Symbols that are not defined in a particular character set are set to the same value as symbol 64; i.e., to 0.
The 8-byte tag string consists of the exact characters SPSSPORT
in the portable file's character set, which can be used to verify that
the file is indeed a portable file.
This record does not have a tag code. It has the following structure:
The product identification record has tag code 1. It consists of a single string field giving the name of the product that wrote the portable file.
The author identification record has tag code 2. It is optional. If present, it consists of a single string field giving the name of the person who caused the portable file to be written.
The subproduct identification record has tag code 3. It is optional. If present, it consists of a single string field giving additional information on the product that wrote the portable file.
The variable count record has tag code 4. It consists of two integer fields. The first contains the number of variables in the file dictionary. The purpose of the second is unknown; it contains the value 161 in all portable files examined so far.
The case weight variable record is optional. If it is present, it indicates the variable used for weighting cases; if it is absent, cases are unweighted. It has tag code 6. It consists of a single string field that names the weighting variable.
Each variable record represents a single variable. Variable records have tag code 7. They have the following structure:
Each variable record can optionally be followed by a missing value record, which has tag code 8. A missing value record has one field, the missing value itself (a floating-point or string, as appropriate). Up to three of these missing value records can be used.
There is also a record for missing value ranges, which has tag code B. It is followed by two fields representing the range, which are floating-point or string as appropriate. If a missing value range is present, it may be followed by a single missing value record.
Tag codes 9 and A represent LO THRU x and
x THRU HI ranges, respectively. Each is followed by a
single field representing x. If one of the ranges is present, it
may be followed by a single missing value record.
In addition, each variable record can optionally be followed by a variable label record, which has tag code C. A variable label record has one field, the variable label itself (string).
Value label records have tag code D. They have the following format:
The data record has tag code F. There is only one tag for all the data; thus, all the data must follow the dictionary. The data is terminated by the end-of-file marker Z, which is not valid as the beginning of a data element.
Data elements are output in the same order as the variable records describing them. String variables are output as string fields, and numeric variables are output as floating-point fields.
PSPP necessarily uses the same format for system files as do the products with which it is compatible. This chapter is a description of that format.
There are three data types used in system files: 32-bit integers, 64-bit
floating points, and 1-byte characters. In this document these will
simply be referred to as int32, flt64, and char,
the names that are used in the PSPP source code. Every field of type
int32 or flt64 is aligned on a 32-bit boundary.
The endianness of data in PSPP system files is not specified. System files output on a computer of a particular endianness will have the endianness of that computer. However, PSPP can read files of either endianness, regardless of its host computer's endianness. PSPP translates endianness for both integer and floating point numbers.
Floating point formats are also not specified. PSPP does not translate between floating point formats. This is unlikely to be a problem as all modern computer architectures use IEEE 754 format for floating point representation.
The PSPP system-missing value is represented by the largest possible
negative number in the floating point format; in C, this is most likely
-DBL_MAX. There are two other important values used in missing
values: HIGHEST and LOWEST. These are represented by the
largest possible positive number (probably DBL_MAX) and the
second-largest negative number. The latter must be determined in a
system-dependent manner; in IEEE 754 format it is represented by value
0xffeffffffffffffe.
System files are divided into records. Each record begins with an
int32 giving a numeric record type. Individual record types are
described below:
The file header is always the first record in the file.
struct sysfile_header
{
char rec_type[4];
char prod_name[60];
int32 layout_code;
int32 case_size;
int32 compressed;
int32 weight_index;
int32 ncases;
flt64 bias;
char creation_date[9];
char creation_time[8];
char file_label[64];
char padding[3];
};
char rec_type[4];int32.
char prod_name[60];int32 layout_code;int32 case_size;int32 compressed;int32 weight_index;int32 ncases;In the general case it is not possible to determine the number of cases
that will be output to a system file at the time that the header is
written. The way that this is dealt with is by writing the entire
system file, including the header, then seeking back to the beginning of
the file and writing just the ncases field. For `files' in which
this is not valid, the seek operation fails. In this case,
ncases remains -1.
flt64 bias;(1 - bias) and (251 - bias) can
be compressed.
char creation_date[9];char creation_time[8];char file_label[64];char padding[3];Immediately following the header must come the variable records. There
must be one variable record for every variable and every 8 characters in
a long string beyond the first 8; i.e., there must be exactly as many
variable records as the value specified for case_size in the file
header record.
struct sysfile_variable
{
int32 rec_type;
int32 type;
int32 has_var_label;
int32 n_missing_values;
int32 print;
int32 write;
char name[8];
/* The following two fields are present
only if has_var_label is 1. */
int32 label_len;
char label[/* variable length */];
/* The following field is present only
if n_missing_values is not 0. */
flt64 missing_values[/* variable length*/];
};
int32 rec_type;int32 type;int32 has_var_label;int32 n_missing_values;int32 print;int32 write;char name[8];int32 label_len;has_var_label is set to 1. It is
set to the length, in characters, of the variable label, which must be a
number between 0 and 120.
char label[/* variable length */];has_var_label is set to 1. It has
length label_len, rounded up to the nearest multiple of 32 bits.
The first label_len characters are the variable's variable label.
flt64 missing_values[/* variable length */];n_missing_values is not 0. It has
the same number of elements as the absolute value of
n_missing_values. For discrete missing values, each element
represents one missing value. When a range is present, the first
element denotes the minimum value in the range, and the second element
denotes the maximum value in the range. When a range plus a value are
present, the third element denotes the additional discrete missing
value. HIGHEST and LOWEST are indicated as described in the chapter
introduction.
The print and write members of sysfile_variable are output
formats coded into int32 types. The LSB (least-significant byte)
of the int32 represents the number of decimal places, and the
next two bytes in order of increasing significance represent field width
and format type, respectively. The MSB (most-significant byte) is not
used and should be set to zero.
Format types are defined as follows:
A
AHEX
COMMA
DOLLAR
F
IB
PIBHEX
P
PIB
PK
RB
RBHEX
Z
N
E
DATE
TIME
DATETIME
ADATE
JDATE
DTIME
WKDAY
MONTH
MOYR
QYR
WKYR
PCT
DOT
CCA
CCB
CCC
CCD
CCE
EDATE
SDATE
Value label records must follow the variable records and must precede the header termination record. Other than this, they may appear anywhere in the system file. Every value label record must be immediately followed by a label variable record, described below.
Value label records begin with rec_type, an int32 value
set to the record type of 3. This is followed by count, an
int32 value set to the number of value labels present in this
record.
These two fields are followed by a series of count tuples. Each
tuple is divided into two fields, the value and the label. The first of
these, the value, is composed of a 64-bit value, which is either a
flt64 value or up to 8 characters (padded on the right to 8
bytes) denoting a short string value. Whether the value is a
flt64 or a character string is not defined inside the value label
record.
The second field in the tuple, the label, has variable length. The
first char is a count of the number of characters in the value
label. The remainder of the field is the label itself. The field is
padded on the right to a multiple of 64 bits in length.
Every value label variable record must be immediately preceded by a value label record, described above.
struct sysfile_value_label_variable
{
int32 rec_type;
int32 count;
int32 vars[/* variable length */];
};
int32 rec_type;int32 count;int32 vars[/* variable length];count elements.
There must be no more than one document record per system file. Document records must follow the variable records and precede the dictionary termination record.
struct sysfile_document
{
int32 rec_type;
int32 n_lines;
char lines[/* variable length */][80];
};
int32 rec_type;int32 n_lines;char lines[/* variable length */][80];n_lines.
Lines shorter than 80 characters are padded on the right with spaces.
int32 Info RecordThere must be no more than one machine int32 info record per
system file. Machine int32 info records must follow the variable
records and precede the dictionary termination record.
struct sysfile_machine_int32_info
{
/* Header. */
int32 rec_type;
int32 subtype;
int32 size;
int32 count;
/* Data. */
int32 version_major;
int32 version_minor;
int32 version_revision;
int32 machine_code;
int32 floating_point_rep;
int32 compression_code;
int32 endianness;
int32 character_code;
};
int32 rec_type;int32 subtype;int32 size;int32 count;int32 version_major;int32 version_minor;int32 version_revision;int32 machine_code;int32 floating_point_rep;int32 compression_code;int32 endianness;int32 character_code;flt64 Info RecordThere must be no more than one machine flt64 info record per
system file. Machine flt64 info records must follow the variable
records and precede the dictionary termination record.
struct sysfile_machine_flt64_info
{
/* Header. */
int32 rec_type;
int32 subtype;
int32 size;
int32 count;
/* Data. */
flt64 sysmis;
flt64 highest;
flt64 lowest;
};
int32 rec_type;int32 subtype;int32 size;int32 count;flt64 sysmis;flt64 highest;flt64 lowest;There must be no more than one auxilliary variable parameter record per system file. This record must follow the variable records and precede the dictionary termination record.
struct sysfile_aux_var_parameter
{
/* Header. */
int32 rec_type;
int32 subtype;
int32 size;
int32 count;
/* Data. */
struct aux_params aux_params[/* variable length */];
};
int32 rec_type;int32 subtype;int32 size;int32. Always set to 4.
int32 count;aux_params divided by 3.
struct aux_params aux_params[];struct aux_params. The order of the elements corresponds
to the order of the variables in the Variable Records. The struct aux_params type is defined as follows:
struct aux_params
{
int32 measure;
int32 width;
int32 alignment;
};
int32 measureint32 widthint32 alignmentThere must be no more than one long variable names record per system file. This record must follow the variable records and precede the dictionary termination record.
struct sysfile_long_variable_names
{
/* Header. */
int32 rec_type;
int32 subtype;
int32 size;
int32 count;
/* Data. */
char var_name_pairs[/* variable length */];
};
int32 rec_type;int32 subtype;int32 size;var_name_pairs member. Always set to 1.
int32 count;var_name_pairs.
char var_name_pairs[/* variable length];count bytes.
Miscellaneous informational records must follow the variable records and precede the dictionary termination record.
Miscellaneous informational records are ignored by PSPP when reading system files. They are not written by PSPP when writing system files.
struct sysfile_misc_info
{
/* Header. */
int32 rec_type;
int32 subtype;
int32 size;
int32 count;
/* Data. */
char data[/* variable length */];
};
int32 rec_type;int32 subtype;int32 size;int32 and flt64, respectively.
int32 count;char data[/* variable length */];size times count bytes of
data.
The dictionary termination record must follow all other records, except for the actual cases, which it must precede. There must be exactly one dictionary termination record in every system file.
struct sysfile_dict_term
{
int32 rec_type;
int32 filler;
};
int32 rec_type;int32 filler;Data records must follow all other records in the data file. There must be at least one data record in every system file.
The format of data records varies depending on whether the data is compressed. Regardless, the data is arranged in a series of 8-byte elements.
When data is not compressed, Every case is composed of case_size
of these 8-byte elements, where case_size comes from the file
header record (see File Header Record). Each element corresponds to
the variable declared in the respective variable record (see Variable Record). Numeric values are given in flt64 format; string
values are literal characters string, padded on the right when
necessary.
Compressed data is arranged in the following manner: the first 8-byte element in the data section is divided into a series of 1-byte command codes. These codes have meanings as described below:
(code - bias) for the case being read, where
code is the value of the compression code and bias is the
variable compression_bias from the file header. For example,
code 105 with bias 100.0 (the normal value) indicates a numeric variable
of value 5.
When the end of the first 8-byte element of command bytes is reached, any blocks of non-compressible values are skipped, and the next element of command bytes is read and interpreted, until the end of the file is reached.
q2c Input FormatPSPP statistical procedures have a bizarre and somewhat irregular
syntax. Despite this, a parser generator has been written that
adequately addresses many of the possibilities and tries to provide
hooks for the exceptional cases. This parser generator is named
q2c.
q2c input.q output.c
q2c translates a .q file into a .c file. It takes
exactly two command-line arguments, which are the input file name and
output file name, respectively. q2c does not accept any
command-line options.
q2c Input Structureq2c input files are divided into two sections: the grammar rules
and the supporting code. The grammar rules, which make up the
first part of the input, are used to define the syntax of the
statistical procedure to be parsed. The supporting code,
following the grammar rules, are copied largely unchanged to the output
file, except for certain escapes.
The most important lines in the grammar rules are used for defining
procedure syntax. These lines can be prefixed with a dollar sign
($), which prevents Emacs' CC-mode from munging them. Besides
this, a bang (!) at the beginning of a line causes the line,
minus the bang, to be written verbatim to the output file (useful for
comments). As a third special case, any line that begins with the exact
characters /* *INDENT is ignored and not written to the output.
This allows .q files to be processed through indent
without being munged.
The syntax of the grammar rules themselves is given in the following sections.
The supporting code is passed into the output file largely unchanged. However, the following escapes are supported. Each escape must appear on a line by itself.
/* (header) */#include directives which include the
headers that are required for the parser generated by q2c.
/* (decls scope) */enums input and output by the q2c parser. scope
must be either local or global. local causes the
declarations to be output as function locals. global causes them
to be declared as static module variables; thus, global is
a bit of a misnomer.
/* (parser) *//* (free) */free function for variables
declared by the parser. Only needs to be invoked if subcommands of type
string are used in the grammar rules.
The grammar rules describe the format of the syntax that the parser
generated by q2c will understand. The way that the grammar rules
are included in q2c input file are described above.
The grammar rules are divided into tokens of the following types:
ID)STRING)The syntax of the grammar rules is as follows:
grammar-rules ::= ID : subcommands .
subcommands ::= subcommand
::= subcommands ; subcommand
The syntax begins with an ID or STRING token that gives the name of the procedure to be parsed. The rest of the syntax consists of subcommands separated by semicolons (;) and terminated with a full stop (.).
subcommand ::= sbc-options ID sbc-defn
sbc-options ::=
::= sbc-option
::= sbc-options sbc-options
sbc-option ::= *
::= +
::= ^
sbc-defn ::= opt-prefix = specifiers
::= [ ID ] = array-sbc
::= opt-prefix = sbc-special-form
opt-prefix ::=
::= ( ID )
Each subcommand can be prefixed with one or more option characters. An asterisk (*) is used to indicate the default subcommand; the keyword used for the default subcommand can be omitted in the PSPP syntax file. A plus sign (+) is used to indicate that a subcommand can appear more than once; if it is not present then that subcommand can appear no more than once. A carat sign (^) is used to indicate that a subcommand must appear at least once.
The subcommand name appears after the option characters.
There are three forms of subcommands. The first and most common form simply gives an equals sign (=) and a list of specifiers, which can each be set to a single setting. The second form declares an array, which is a set of flags that can be individually turned on by the user. There are also several special forms that do not take a list of specifiers.
Arrays require an additional ID argument. This is used as a
prefix, prepended to the variable names constructed from the
specifiers. The other forms also allow an optional prefix to be
specified.
array-sbc ::= alternatives
::= array-sbc , alternatives
alternatives ::= ID
::= alternatives | ID
An array subcommand is a set of Boolean values that can independently be turned on by the user, listed separated by commas (,). If an value has more than one name then these names are separated by pipes (|).
specifiers ::= specifier
::= specifiers , specifier
specifier ::= opt-id : settings
opt-id ::=
::= ID
Ordinary subcommands (other than arrays and special forms) require a list of specifiers. Each specifier has an optional name and a list of settings. If the name is given then a correspondingly named variable will be used to store the user's choice of setting. If no name is given then there is no way to tell which setting the user picked; in this case the settings should probably have values attached.
settings ::= setting
::= settings / setting
setting ::= setting-options ID setting-value
setting-options ::=
::= *
::= !
::= * !
Individual settings are separated by forward slashes (/). Each
setting can be as little as an ID token, but options and values
can optionally be included. The * option means that, for this
setting, the ID can be omitted. The ! option means that
this option is the default for its specifier.
setting-value ::=
::= ( setting-value-2 )
::= setting-value-2
setting-value-2 ::= setting-value-options setting-value-type : ID
setting-value-restriction
setting-value-options ::=
::= *
setting-value-type ::= N
::= D
setting-value-restriction ::=
::= , STRING
Settings may have values. If the value must be enclosed in parentheses,
then enclose the value declaration in parentheses. Declare the setting
type as n or d for integer or floating point type,
respectively. The given ID is used to construct a variable name.
If option * is given, then the value is optional; otherwise it
must be specified whenever the corresponding setting is specified. A
“restriction” can also be specified which is a string giving a C
expression limiting the valid range of the value. The special escape
%s should be used within the restriction to refer to the
setting's value variable.
sbc-special-form ::= VAR
::= VARLIST varlist-options
::= INTEGER opt-list
::= DOUBLE opt-list
::= PINT
::= STRING (the literal word STRING) string-options
::= CUSTOM
varlist-options ::=
::= ( STRING )
opt-list ::=
::= LIST
string-options ::=
::= ( STRING STRING )
The special forms are of the following types:
VARVARLISTPV_* options to the call to parse_variables.
INTEGERINTEGER LISTDOUBLEDOUBLE LISTPINTSTRINGCUSTOMint custom_name (void). It should return 0
on failure (when it has already issued an appropriate diagnostic), 1 on
success, or 2 if it fails and the calling function should issue a syntax
error on behalf of the custom handler.
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