regular expression question
Hi Erin,
Please read ?grep. It is clearly not the function you want (neither
is strsplit() either really). This does what you want and you can
modify for upper/lower case if you need it. Also note that regular
expressions exist separate from R, so while ":" may have seemed
natural to select a range in R, it has a very different function in
regexp.
gsub("[^A-Za-z]", "", names(funky))
Best regards,
Josh
On Mon, Apr 11, 2011 at 10:49 PM, Erin Hodgess <erinm.hodgess at gmail.com> wrote:
Dear R People: I have a data frame with the following column names:
names(funky)
?[1] "UHD.1" ? "UHD.2" ? "UHD.3" ? "UHD.4" ? "L..W..1" "L..W..2" "L..W..3" ?[8] "L..W..4" "B..W..1" "B..W..2" "B..W..3" "B..W..4" "W..B..1" "W..B..2" [15] "W..B..3" "W..B..4" "B..G..1" "B..G..2" "B..G..3" "B..G..4" I would like to extract the letters from them; no periods, no numbers. I tried the following:
grep("[A:Z]",names(funky))
integer(0) But this doesn't do it. I've also been experimenting with strsplit, but no luck yet. Any help would be much appreciated. Thanks, Sincerely, Erin -- Erin Hodgess Associate Professor Department of Computer and Mathematical Sciences University of Houston - Downtown mailto: erinm.hodgess at gmail.com
______________________________________________ R-help at 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.
Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.com/