On Feb 22, 2010, at 10:25 AM, Marianne Promberger wrote:
> Dear list,
>
> I have two vectors:
>
> x <- c("one","two")
> y <- paste(rep(x,2),"blah")
>
> I want to replace all occurrences of each element of x in y with
> something else, so that y looks like this:
>
> y
> [1] "something else blah" "something else blah" "something else blah"
> [4] "something else blah"
>
> I can do this using a loop:
>
> for ( i in 1:length(x) ) {
> y <- gsub(x[i],"something else",y)
> }
>
> Surely, there must be a less kludgy way?
>
> I tried looking at the different apply()s but am not getting anywhere,
> partly because I lack the mental flexibility to combine the fact that
> I am applying gsub() to y but now want to apply that to x ... erm. :/
>
> Marianne
You can use "|" to specify a logical "or" in the search regex:
> gsub("one|two", "something else", y)
[1] "something else blah" "something else blah" "something else blah"
[4] "something else blah"
Thus:
> paste(x, collapse = "|")
[1] "one|two"
and finally:
> gsub(paste(x, collapse = "|"), "something else", y)
[1] "something else blah" "something else blah" "something else blah"
[4] "something else blah"
See ?regex and ?paste
HTH,
Marc Schwartz
______________________________________________
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.
