Hi Lisa, On Tue, Apr 26, 2011 at 2:09 PM, Lisa <lisa...@gmail.com> wrote: > Dear all, > > I just want to determine if the characters in a character string are the > same or not. For example, > > temp <- c("aa", "aA", "ab") > > How do I determine the first one have the two same “a”, and the second and > third have the different characters? Thanks in advance.
Is this what you're looking for? testchar <- function(x) { substring(x, 1, 1) == substring(x, 2, 2) } > testchar("aa") [1] TRUE > testchar("aB") [1] FALSE > > > temp <- c("aa", "aA", "ab") > > sapply(temp, testchar) aa aA ab TRUE FALSE FALSE -- Sarah Goslee http://www.functionaldiversity.org ______________________________________________ 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.