Dear all I'm pretty sure that I'm approaching the problem in a wrong way. Suppose the following character vector: > (x[1:10] <- paste(x[1:10], sample(1:10, 10), sep='')) [1] "a10" "b7" "c2" "d3" "e6" "f1" "g5" "h8" "i9" "j4" > x [1] "a10" "b7" "c2" "d3" "e6" "f1" "g5" "h8" "i9" "j4" "k" "l" "m" "n" [15] "o" "p" "q" "r" "s" "t" "u" "v" "w" "x" "y" "z" "1" "2" [29] "3" "4" "5" "6" "7" "8" "9" "10" "11" "12" "13" "14" "15" "16" [43] "17" "18" "19" "20" "21" "22" "23" "24" "25" "26"
How do you test whether the elements of the vector contain at least one letter (or at least one digit) and obtain a logical vector of the same dimension? I came up with the following awkward function: is_letter <- function(x, pattern=c(letters, LETTERS)){ sapply(x, function(y){ any(sapply(pattern, function(z) grepl(z, y, fixed=T))) }) } > is_letter(x) a10 b7 c2 d3 e6 f1 g5 h8 i9 j4 k l m n o TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE p q r s t u v w x y z 1 2 3 4 TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE FALSE FALSE FALSE FALSE 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE 20 21 22 23 24 25 26 FALSE FALSE FALSE FALSE FALSE FALSE FALSE > is_letter(x, 0:9) ##function slightly misnamed a10 b7 c2 d3 e6 f1 g5 h8 i9 j4 k l m n o TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE FALSE FALSE FALSE FALSE FALSE p q r s t u v w x y z 1 2 3 4 FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE TRUE TRUE TRUE TRUE 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE 20 21 22 23 24 25 26 TRUE TRUE TRUE TRUE TRUE TRUE TRUE Is there a nicer way to do this? Regards Liviu -- Do you know how to read? http://www.alienetworks.com/srtest.cfm http://goodies.xfce.org/projects/applications/xfce4-dict#speed-reader Do you know how to write? http://garbl.home.comcast.net/~garbl/stylemanual/e.htm#e-mail ______________________________________________ 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.