| FitPeakByIsotopicRatio {CorrectOverloadedPeaks} | R Documentation |
Extrapolate a flat top peak using isotopic ratios.
Description
FitPeakByIsotopicRatio will take a data frame containing peak data for retention time ('RT'), as well as
mass and intensity information of M0, M+1 and M+2 and extrapolate all points above a certain threshold for Int_M0
based on further parameters using an IsotopicRatio approach.
Usage
FitPeakByIsotopicRatio(cor_df = NULL, idx = NULL, silent = TRUE)
Arguments
cor_df |
A data frame containing information about the overloaded area; columns=(Scan, RT, mz0, int0, mz1, int1, mz2, int2, modified). |
idx |
If not NULL, 'idx' is expected to specify points to correct explicitly (as a numeric-vector within 1:length(x)). |
silent |
For testing purposes some QC-plot will be generated if silent=FALSE. |
Details
Isotopic ratios within ion traces of molecules can be considered stable. If this ratio is changed because one molecule,
let's say the M+0, is exceeding the detector range while another (say M+1) is still quantifiable, we therefore may
attempt to modify M+0 by multiplying the values of M+1 with a constant (the stable ratio). This constant is determined
ideally from the values within the peak front.
As this function is mainly used internally (CorrectOverloadedPeaks), it is not very flexible with respect
to the input format. Please prepare a dataframe according to the parameter specifications or process a file using
CorrectOverloadedPeaks with testing=TRUE, which will generate a list structure of such dataframes.
Value
An annotated plot of the mass spectrum and detailed information within the console. Main result will be returned invisible.