Dear All, I was using GEOquery package After doing required steps I did this probesets <- Table(GPLList(gse6901)[[1]])$ID > data.matrix <- log2(do.call("cbind", lapply(GSMList(gse6901), function(x) { + tab <- Table(x) + mymatch <- match(probesets, tab$ID_REF) + return(tab$VALUE[mymatch]) + }))) Error in log(c("27", "59.8", "34.1", "110.5", "130.3", "569.3", "210.5", : Non-numeric argument to mathematical function Can u please help me solving this error as I am not able to understad what that error means I shall be very thankful for ur kind help -- Hemant Ritturaj Kushwaha [[alternative HTML version deleted]]