I have a similar problem. I have a dataset and an element. If the element is equal to "YY", I want to take the first column of the dataset, otherwise I want to take the second column. The following does not work, as it only evaluates the first element. Any idea?
a=c("AAAXXX","BBBXXX") a=merge(a,c("AAA","BBB")) b="YY" > ifelse(b=="YY",a,substr(a,1,3)) [1] "AAAXXX" -- View this message in context: http://r.789695.n4.nabble.com/inefficient-ifelse-tp3330423p4512579.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.