Get the differences of two GC/LC-MS data
submd(data1, data2, mzstep = 0.1, rtstep = 0.01)data file path of first data
data file path of second data
the m/z step for generating matrix data from raw mass spectral data
the alignment accuracy of retention time, e.g. 0.01 means the retention times of combined data should be the same at the accuracy 0.01s. Higher rtstep would return less scans for combined data
list four matrix with the row as scantime in second and column as m/z, the first matrix refer to data 1, the second matrix refer to data 2, the third matrix refer to data1 - data2 while the fourth refer to data2 - data1, minus values are imputed by 0
if (FALSE) {
library(faahKO)
cdfpath <- system.file('cdf', package = 'faahKO')
cdffiles <- list.files(cdfpath, recursive = TRUE, full.names = TRUE)
matrix <- submd(cdffiles[1],cdffiles[7])
}