I am conducting a very simple t test for two genes using lapply (i try to avoid loop since i will have thousands of genes later on). however, I got strange error msg like the followings. It looks that R is complaining my factor has only one level, which is not the case (I check many times).
> result<- lapply(split(all,all$CHIPEXP_NAME),function(x) > lm(logvalue~treatment,x)) Error in `contrasts<-`(`*tmp*`, value = "contr.treatment") : contrasts can be applied only to factors with 2 or more levels can anyone help me to dissect this problem? thanks in advance. -- View this message in context: http://r.789695.n4.nabble.com/strange-error-msg-from-lapply-and-lm-tp2124042p2124042.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.