Hi, In my data.frame I wanted to essentially write If(Test) c*d else c+d
but that doesn't work. I found I could do it mathematically, but it seems forced and won't scale well for nested logic. I have two examples below writing columns e & f, but I don't think the code is self-documenting as it depends on knowing that Test is a TRUE/FALSE. Is there a better way to do the following? Thanks, Mark DF <- data.frame(cbind(a=1:4, b=1:2, c=1:8, d=1:16, e=0, f=0)) DF$Test <- with(DF, a == b) DF$e = (DF$c*DF$d) * DF$Test + (DF$c+DF$d) * !DF$Test DF$f = with(DF, (c*d)*Test + (c+d)*!Test) DF ______________________________________________ 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.
