Re: [R] Using grep() to subset lines of text

ppaarrkk wrote: I have two vectors, a and b. b is a text file. I want to find in b those elements of a which occur at the beginning of the line in b. I have the following code, but it only returns a value for the first value in a, but I want both. Any ideas please. a = c(2,3) b = NULL b[1] =

Re: [R] Using grep() to subset lines of text

Try this. For each character x in s, if "x" is punctuation it is replaced with "\\x" otherwise with "[x]" : library(gsubfn) gsubfn('.', ~ if (any(grep("[[:punct:]]", x))) paste0('\\', x) else paste0('[', x, ']'), s) See http://gsubfn.googlecode.com On Sat, Nov 29, 2008 at 10:09 PM, Stavros Mac

Re: [R] Using grep() to subset lines of text

But I don't want to ignore all regexp's -- I want to build a regexp which contains string components which are parameters. -s On Sat, Nov 29, 2008 at 6:51 PM, Gabor Grothendieck <[EMAIL PROTECTED] > wrote: > grep has a fixed = TRUE argument if you want to ignore all regexp's. > > On

Re: [R] Using grep() to subset lines of text

grep has a fixed = TRUE argument if you want to ignore all regexp's. On Sat, Nov 29, 2008 at 3:55 PM, Stavros Macrakis <[EMAIL PROTECTED]> wrote: > Hmm, this brings up an interesting question. What if the string I'm looking > for contains escape characters? For example, grep( paste( "^", "(ab)"

Re: [R] Using grep() to subset lines of text

Hmm, this brings up an interesting question. What if the string I'm looking for contains escape characters? For example, grep( paste( "^", "(ab)" ), c("ab","(ab)") ) => c(1), not c(2). I couldn't find an equivalent to Emacs's regexp-quote, which would let me write regexp.quote("(ab)") => "\\(ab\

Re: [R] Using grep() to subset lines of text

Try this: > a <- 2:3 > b <- c("aaa 2 aaa", "2 aaa", "3 aaa", "aaa 3 aaa") > > re <- paste("^(", paste(a, collapse = "|"), ")", sep = "") > re [1] "^(2|3)" > grep(re, b, value = TRUE) [1] "2 aaa" "3 aaa" On Sat, Nov 29, 2008 at 7:00 AM, ppaarrkk <[EMAIL PROTECTED]> wrote: > > I have two vectors, a

[R] Using grep() to subset lines of text

I have two vectors, a and b. b is a text file. I want to find in b those elements of a which occur at the beginning of the line in b. I have the following code, but it only returns a value for the first value in a, but I want both. Any ideas please. a = c(2,3) b = NULL b[1] = "aaa 2 aaa" b[2] =