On May 20, 2011, at 11:57 AM, Kang Min wrote:
Hi all, I'm trying to subset a pattern in a vector. Each argument has 6 letters, and I need those that start with Z and end with Z. e.g. x <- c("ZFHSJK", "ZFHJKZ","ZIOPWE","ZLKJSD","ZKFLPZ") I've looked up other discussions but still can't seem to find the answer.
You may need to study the regex page a bit longer the "^" is the beginning of a string ".+" will math can arbitrarily long string of anything and "$" indicates the end of a string > x <- c("ZFHSJK", "ZFHJKZ","ZIOPWE","ZLKJSD","ZKFLPZ") > grep("^Z.+Z$", x) [1] 2 5 > grep("^Z.+Z$", x, value=TRUE) [1] "ZFHJKZ" "ZKFLPZ"
Thanks. Kangmin ______________________________________________ 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.
David Winsemius, MD West Hartford, CT ______________________________________________ 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.