I am running this small program: x <- factor(c("A","B","A","C")) y <- c(1,2,3,4) w <-data.frame(x,y) if (w$x=="A"){ w$z=1 } w And I obtain:
x y z 1 A 1 1 2 B 2 1 3 A 3 1 4 C 4 1 And not x y z 1 A 1 1 2 B 2 NA 3 A 3 1 4 C 4 NA Like I should obtain. What am I doing wrong? Please notice that I get a warning approximately saying - translated from italian: In if (w$x == "A") { : the condition length > 1 and only the first element will be used Thanks, Luca ______________________________________________ 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.