diffGetPeaks: Find pairs of mass peaks corresponding to a specific mass

In kbseah/mass2adduct: Mass Spectrometry Imaging Molecular Adduct Finder

Description

From a set of all possible mass pairs, find all pairs corresponding to a specific mass difference, which might represent a molecular transformation of interest.

Usage

diffGetPeaks(diff, mass = NULL, ppm = 2, mDa = NULL)

Arguments

diff	massdiff; output from massdiff
mass	numeric; mass of putative adduct or parent ion in m/z units
ppm	numeric; the peak width (uncertainty) of the calculated peaks in proportional units, as parts per million (default: 2)
mDa	numeric; the peak width (uncertainty) of the calculated peaks in absolute mass units, as milliDaltons (default: NULL)

Details

There are two options for setting a cutoff to match a given mass to a given target value. The cutoff can be either proportional to the mass (and expressed as parts per million ppm) or a flat absolute value (in milliDaltons mDa). ppm is used by default. If a value for mDa is specified, then any value given to ppm is ignored. The ppm or mDa values are usually reported by the peak-picking software used.

Value

Subset of the original massdiff object where the mass difference or parent ion is close to the specified mass of interest within the uncertainty specified

kbseah/mass2adduct documentation built on June 9, 2021, 9:20 p.m.