On Fri, May 15, 2009 at 3:38 PM, Romain Francois <romain.franc...@dbmail.com> wrote: > Hi, > > You can either parse and eval the string you are making, as in: > > eval( parse( text = paste("avg_",colname, " <- 0;", sep='') ) ) > > > Or you can do something like this: > > df[[ paste( "avg_", colname, sep = "" ) ]] <- 0 >
Thanks you so much! I used the first version and it worked. What puzzles me, is that I am not able to use <- instead of = (my R book says the two can be exchanged) or break the command into different parts and execute them one after another. I get various error messages when I try: eval( parse( text <- paste("avg_",colname, " <- 0;", sep='') ) ) or text = paste("avg_",colname, " <- 0;", sep='') parse(text) eval(parse(text)) Anyway, thanks a lot - you greatly improved the likelihood of me not working on the weekend! Best - P ______________________________________________ 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.