Dear All, I need to print the column names of variables before each block of output, for a nested model with 2 levels (3 phenotypes * 10 markers). This is so that my output is labeled, and I know which combination of factors produces which set of REML estimates. Currently my output looks like this: [1] "Phenotype" NULL ##this is where I want to insert colnames OR numbers 1-3 [1] "Marker" NULL ##insert colnames again OR numbers 1-10 Linear mixed model fit by REML - (data) - (data) Random effects: -(data) . . [1] "Marker" NULL Linear mixed model fit by REML - (data) - (data) Random effects: . . (3*10 combinations) My code is as follows: vc<-read.table("...",header=T) vcdf<-data.frame(vc) vcdf[2:13]<-lapply(vcdf[2:13,factor) colms<-(vcdf)[4:13] ## these are the 10 markers. I put them in a new variable to make running the loop simple. phen<-(vcdf)[14:16] ##these are the 3 phenotypes for( c in phen) { print("Phenotype") print(colnames(c)) for( f in colms) { print("Marker") print(colnames(f)) fit<-lmer(data=vcdf, c~1 + (1|family/f)) print(summary(fit)) }} Any pointers on how to print either column names, or a sequence of numbers? Thanks a lot for your help, Aditi ---------------------- A Singh Aditi.Singh at bristol.ac.uk School of Biological Sciences University of Bristol