a Distance function based on matching peaks — specDist.meanMZmatch • xcms

This method calculates the distance of two sets of peaks.

Usage

specDist.meanMZmatch(peakTable1, peakTable2, matchdist=1, matchrate=1,
                     mzabs=0.001, mzppm=10, symmetric=TRUE)

Methods

peakTable1 = "matrix", peakTable2 = "matrix": specDist.meanMZmatch(peakTable1, peakTable2, matchdist=1, matchrate=1, mzabs=0.001, mzppm=10, symmetric=TRUE)

Details

The result of the calculation is a weighted sum of two values. Value one is the mean absolute difference of the matching peaks, value two is the relation of matching peaks and non matching peaks. if no distance is calculated (for example because no matching peaks were found) the return-value is NA.

Arguments

peakTable1: a Matrix containing at least m/z-values, row must be called "mz"
peakTable2: the matrix for the other mz-values
mzabs: maximum absolute deviation for two matching peaks
mzppm: relative deviations in ppm for two matching peaks
symmetric: use symmetric pairwise m/z-matches only, or each match
matchdist: the weight for value one (see details)
matchrate: the weight for value two

Author

Joachim Kutzera, jkutzer@ipb-halle.de