\name{giaever} \alias{giaever} \docType{data} \title{Yeast Gene-Knockout Fitness Data} \description{ This data set contains fitness deficiency scores from gene knockout experiments involving yeast grown under a variety of altered environments (e.g. acid, heat, sorbitol, etc.) } \usage{data(giaever)} \format{A matrix whose rows are the 5922 genes knocked out and whose columns are the 32 experimental conditions.} \source{\url{http://gobi.lbl.gov/YeastFitnessData}} \references{Giaever, G. et al. 2002 ``Functional profiling of the Saccharomyces cerevisiae genome.'' Nature \bold{418}, 387--391. } \examples{ data(giaever) ## Find the 3000 most variable genes, according to sd/mean: varMeas <- function(vec, na.rm=TRUE) { if(na.rm) vec <- vec[!is.na(vec)] if(length(vec) == 0) measure <- NA else measure <- sd(vec)/mean(vec) return(measure) } variability <- apply(giaever, 1, varMeas) rks <- rank(variability) giaever3000 <- giaever[rks>length(rownames(giaever))-3000,] } \keyword{datasets}