These are great, thanks. I always forget about paste(). === Richard Sherman rss.pdx using gmail.com > On Aug 22, 2018, at 17:56, Fox, John <jfox using mcmaster.ca> wrote: > > fm <- vector("character",6) > fm[1]<- "mpg ~ hp" > for(i in 2:6)fm[i]<- paste0(fm[i-1]," + I(hp^", i,")")