search for: alternativeley

.... e.g. df <- data.frame(x = sample(4), y = sample(4), z = sample(4)) I can extract column z by: df$z or df[3] I can also extract columns x,y by: df[1:2] or by df[-3]. Is it possible to extract x,y columns in a "symbolic" fashion i.e. by equivalent of df[-z] (which is illegal) ??? Or alternativeley, is there an equivalent of "index" function, which would return index of the column given name ? Ryszard

Hi I am analysing a dataset of 40 samples each with 90,000 intensity measures for various peptides. I am trying to identify the Biomarkers (i.e. most significant peptides). I beleive that PLS with jack knifing, or alternativeley CMV(cross-model-validation) are multivariateThe 40 samples belong to four different groups. I have managed to conduct the plsr using the commands: BHPLS1 <- plsr(GroupingList ~ PCIList, ncomp = 10, data = PLSdata, validation = "LOO") and BHPLS1 <- plsr(GroupingList ~ PCILis...