defineKnots {ptairMS} | R Documentation

## Define the knots location

### Description

`defineKnots` function determine the knots location for a ptrSet or ptrRaw object. There is three possibilities :

- `method = expiration` in the expiration periods, a knots is placed every `knotsPeriod` seconds, and 1 knots in the middle of two expiration, one at begin and at the end

- `method= uniforme`, the knots are placed uniformly every `knotsPeriod` time points

- give in `knotsList` a list of knot, with all base name file in name of the list element. All file must be informed. The knots location must be contained in the time axis

### Usage

    defineKnots(
      object,
      knotsPeriod = 3,
      method = c("expiration", "uniform", "manual")[1],
      knotsList = NULL,
      ...
    )

    ## S4 method for signature 'ptrRaw'
    defineKnots(
      object,
      knotsPeriod = 3,
      method = c("expiration", "uniform")[1],
      knotsList = NULL,
      timeLimit = list(NULL)
    )

    ## S4 method for signature 'ptrSet'
    defineKnots(
      object,
      knotsPeriod = 3,
      method = c("expiration", "uniform")[1],
      knotsList = NULL
    )

### Arguments

`object` | ptrSet object
`knotsPeriod` | the period in second (times scale) between two knots for the two dimensional modelization
`method` | expiration or uniform
`knotsList` | a list of knot location for each files, with all base name file in name of the list element
`...` | not used
`timeLimit` | index time of the expiration limits and background

### Value

numeric vector of knots

a list with numeric vector of knots for each file

### Examples

    library(ptairData)
    dirRaw <- system.file("extdata/exhaledAir", package = "ptairData")
    exhaledPtrset <- createPtrSet(dir=dirRaw, setName="exhaledPtrset",
    mzCalibRef = c(21.022, 60.0525), fracMaxTIC = 0.7, saveDir = NULL )

    #### placed knots every 2 times points
    exhaledPtrset <- defineKnots(exhaledPtrset ,knotsPeriod=2,method='uniform')

    #### placed knots every 3 times points in the expiration (default)
    exhaledPtrset <- defineKnots(exhaledPtrset ,knotsPeriod=3,method='expiration')

[Package ptairMS version 1.2.0 Index]