## load package
library("MALDIquant")
## create four MassPeaks objects and add them to the list
p <- list(createMassPeaks(mass=1:2, intensity=1:2),
createMassPeaks(mass=1:3, intensity=1:3),
createMassPeaks(mass=1:4, intensity=1:4),
createMassPeaks(mass=1:5, intensity=1:5))
## merge all four MassPeaks objects into a single new one
## by sum their intensities
## (no labels, returns only one new MassPeaks object)
mergedPeaks <- mergeMassPeaks(p, method="sum")
## only merge MassPeaks objects in a group
## (two different labels, returns a list of two new MassPeaks objects)
groups <- factor(c("a", "a", "b", "b"), levels=c("a", "b"))
mergedPeaks <- mergeMassPeaks(p, labels=groups, method="mean")
## the same, but treat NA as zero
mergedPeaks <- mergeMassPeaks(p, labels=groups, method="mean", ignore.na=FALSE)
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