Hi all, Please forgive me if it has been posted and answered before. I spent several hours trying to use read.SMD() or read.SMD2() in the "marray" package to generate marrayRaw object, but failed. I downloaded the raw cDNA data from SMD. Error message is: Error in "[.data.frame"(dat, , info.id) : undefined columns selected I have also tried several other SMD datasets, but had the same problem. Can somebody help me out? Many thanks. Dongxiao ________________________________________________ Dongxiao Zhu, Graduate Student Bioinformatics Program The University of Michigan