findFragment {CluMSID} | R Documentation

## Find spectra that contain a specific fragment

### Description

`findFragment` is used to find spectra that contain a specific fragment ion. Its sister function is `findNL`, which finds specific neutral losses. Both functions work analogous to `getSpectrum`.

### Usage

    findFragment(featlist, mz, tolerance = 1e-05)

### Arguments

`featlist` | a list that contains only objects of class `MS2spectrum`
`mz` | The mass-to-charge ratio of the fragment ion of interest.
`tolerance` | The m/z tolerance for the fragment ion search. Default is `1E-05`, i.e. +/- 10ppm.

### Value

If the respective fragment is only found in one spectrum, the output is an object of class `MS2spectrum`; if it is found in more than one spectrum, the output is a list of `MS2spectrum` objects.

### Examples

    load(file = system.file("extdata",
        "annotatedSpeclist.RData",
        package = "CluMSIDdata"))
    putativeAQs <- findFragment(annotatedSpeclist, 159.068)

[Package CluMSID version 1.3.1 Index]