Dear Johannes, You can use cascading ifelse()s:
> df$A <- with(df, ifelse(A <= 3, "x", ifelse(A > 3 & A <= 8, "y", "z"))) > df$A [1] "x" "x" "x" "y" "y" This command assumes that you want all values that don't map into "x"s and "y"s to be "z"s, but you could adapt it if that's not what you want (and no values in your example become "z"s anyway). I hope this helps, John -------------------------------- John Fox Senator William McMaster Professor of Social Statistics Department of Sociology McMaster University Hamilton, Ontario, Canada web: socserv.mcmaster.ca/jfox > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf Of johannes rara > Sent: March-30-10 7:31 AM > To: r-help@r-project.org > Subject: [R] How to recode variables using base R > > Hi, > > Is there an efficient way recoding variables in a data.frame using > base R? My purpose is to create > new variables and attach them into old data.frame. The basic idea is > shown below, but how to create recoding for A, B and C and assing them > into new variables? > > df <- data.frame(A = c(1:5), > B = c(3,6,2,8,10), > C = c(0,15,5,9,12)) > > df$A[df$A <= 3] <- "x" > df$A[df$A > 3 & df$A <= 8] <- "y" > df$A[df$A <= 16] <- "z" > > Thanks, > -J > > ______________________________________________ > 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. ______________________________________________ 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.
