The following line should do what you want. > myContrasts<-c("t1-t2","t1-3","t2-t3") contrast.matrix <- eval(as.call(c(as.symbol("makeContrasts"),as.list (myContrasts),levels=list(design)))) It's the same convention as making calls to R functions through C code. Cheers, On 11-Mar-06, at 3:16 PM, Francois Pepin wrote: > Hi everyone, > > is there a way to automate calls to makeContrasts? Right now, all the > contrasts have to be typed in or hard-coded. We're dealing with a > couple > of hundreds of samples and it would make my life a lot easier if we > could generate everything automatically. I've looked briefly in the > archives but didn't find anything. > > Ideally, I would want to have a way to do: > > myContrasts<-c("t1-t2","t1-3","t2-t3") > contrast.matrix<-makeContrasts(myContrasts,levels=design) > > I haven't found a way to properly go around the 'substitute(list > (...))' > call inside of makeContrasts. > > Right now, I'm writing code to output the proper call and copy/ > paste it > back in the console. > > Another alternative would be to create the contrast matrix myself. > That > would be a more elegant way of doing it, but I don't quite feel > comfortable enough (yet) with design matrices for that. > > Francois > > _______________________________________________ > Bioconductor mailing list > Bioconductor at stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/bioconductor Greg Finak PhD Candidate McGill Center For Bioinformatics (W)(514)398-7071 x09317 finak at mcb.mcgill.ca