apply is your friend: fn <- function (x, a, b) { if (x < a) return(a) else if (x > b) return(b) else x }
apply(mat, c(1,2), fn, -4, 3) [,1] [,2] [,3] [,4] [1,] -4 -1 3 -4 [2,] -4 0 3 -3 [3,] -3 1 3 -2 [4,] -2 2 -4 -1 HTH, Simon. Kartik Pappu wrote: > Hi all, > > I have a square (a x a) matrix with values in a range. For example: > > [,1] [,2] [,3] [,4] > [1,] -5 -1 3 -4 > [2,] -4 0 4 -3 > [3,] -3 1 5 -2 > [4,] -2 2 -5 -1 > > I want to take any number smaller than -4 (in this example -5) and > replace it with -4 and similarly take any number greater than 3 (in > this case 4 and 5) and replace it with 3. The other numbers (and the > overall structure of the matrix should remain unchanged. > > Seems like something that would use an "if a<b then c else d" kind of > logic, but I cannot figure out how to manipulate the entire matrix. > > Thanks much > > Kartik > > ______________________________________________ > R-help@stat.math.ethz.ch 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. > > -- Simon Blomberg, B.Sc.(Hons.), Ph.D, M.App.Stat. Centre for Resource and Environmental Studies The Australian National University Canberra ACT 0200 Australia T: +61 2 6125 7800 email: Simon.Blomberg_at_anu.edu.au F: +61 2 6125 0757 CRICOS Provider # 00120C ______________________________________________ R-help@stat.math.ethz.ch 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.