findNeutralLoss {CAMERA} | R Documentation

## Find pseudospectra that contains a specific neutral loss

### Description

The method searches in every pseudospectra for a distance between two ions matching a provided mass difference. It returns a xcmsSet object containing the matching peaks.

### Usage

      findNeutralLoss(object, mzdiff=NULL, mzabs=0, mzppm=10)

### Arguments

`object` | xsAnnotate object
`mzdiff` | neutral loss in Dalton
`mzabs` | absolut allowed mass difference
`mzppm` | relative allowed mass difference

### Details

The function needs a xsAnnotate object after groupCorr or groupFWHM. The resulting object is a artificial xcmsSet, where the peaks with the specific neutral loss are stored in xcmsSet@peaks.

### Author(s)

Carsten Kuhl <ckuhl@ipb-halle.de>

### Examples

      library(CAMERA)
      file <- system.file('mzdata/MM14.mzdata', package = "CAMERA")
      xs   <- xcmsSet(file, method="centWave", ppm=30, peakwidth=c(5,10))
      an   <- xsAnnotate(xs)
      an   <- groupFWHM(an)
      #Searches for Peaks with water loss
      xs.pseudo <- findNeutralLoss(an,mzdiff=18.01,mzabs=0.01)
      xs.pseudo@peaks #show Hits

[Package CAMERA version 1.50.0 Index]