On 12-02-2013, at 11:09, Robert Latest <boblat...@gmail.com> wrote: > Hello all, > > given two vectors X and Y I'd like to receive a vector Z which > contains, for each element of X, the index of the corresponding > element in Y (or NA if that element isn't in Y). > > Example: > > x <- c(4,5,6) > y <- c(10,1,5,12,4,13,14) > > z <- findIndexIn(x, y) > z > [1] 5 3 NA > > 1st element of z is 5, because the 1st element of x is at the 5th position in > y > 2nd element of z is 3, because the 2nd element of x is at the 3rd position in > y > 3rd element of z is NA, because the 3rd element of x is not in y > > Of course I can write the function findIndexIn() using a for loop, but > in 80% of cases when I felt the urge to use "for" in R it turned out > that there was already some builtin operator or function that did the > trick. > > Suggestions, anyone? > Thanks, >
?match match(x,y) Berend ______________________________________________ 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.
