Astro::Constants version 0.07 ----------------------------- This module provides a large number of physical constants which are useful to Astronomers. The module itself is essentially a wrapper around the astroconst package of Jeremy Balin, whose home page is currently http://clavelina.as.arizona.edu/astroconst/ The module allows you to write code like use Astro::Constants::CGS qw(:long); print "The Schwarzschild radius of the sun is ", 2 * GRAVITATIONAL * MASS_SOLAR / LIGHT_SPEED ** 2, " centimetres\n"; or use Astro::Constants::MKS qw(:short); print "The Schwarzschild radius of the sun is ", 2 * $A_G * $A_msun / $A_c ** 2, " metres\n"; It also provides some subroutines to access the list of constants available, a description of those constants, the precision associated with a constant and print out numbers in a easier to read form. Why not just use astroconst directly? ------------------------------------- A good question. This module is not required to use the astroconst package, but it does provide a more structured, "perlish", interface to the data from the astroconst package. Requirements ------------ Version 5.6.0 or later of perl. Although not needed by this module, the L package (http://pdl.perl.org/) is strongly suggested if you are interested in doing any serious numerical computation in perl. The astroconst package is *not* required, since this module contains all the necessary information from the Files ----- README - this file astroconst.dat - the original data file from Jeremy build.PL - during the make, it parses the 2 input files and writes the CGS and MKS modules convert.pl - a little script for J and I to play with. it converts astroconst.dat to factory.dat (new format) factory.dat - new format for the data file including short name, long name, description, CGS value MKS value and precision everything else is already listed in the MANIFEST file Installation ------------ The module follows the standard perl module installation method, namely: perl Makefile.pl make make test make install If you want to add in your own constants or override the factory defaults, run make, edit the site_const.dat file and then run make again. If you have a pre-existing site_const.dat file, drop it in place before running make. The Future ---------- The file astroconst.dat is the officially sanctioned constants from Jeremy. Site specific constants go in the site_const.dat file. Edit this file before you run make. If you have an existing site_const.dat file, it will NOT be overwritten. We are hoping to move to an XML format for the constants. This could lead to a dependancy on XML::Parser for generating site-specific constants. Slashdot commentary on the new XML Schema 1.1 spec is at http://developers.slashdot.org/developers/03/01/23/228230.shtml?tid=95&tid=156 Author & Copyright ------------------ Boyd Duffee, perl@cs.keele.ac.uk Copyright 2003, Boyd Duffee astroconst.dat belongs to Jeremy Bailin All rights reserved. There is no warranty. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. (Debian users may assume the use of the Artistic Licence)