You want to replace all 1s each with the same random nuumber from the uniform distribution, then all 2s each with the same random nuumber from the uniform distribution, and so forth? Are the arguments (i.e., the min and max of the distribution) to each call to runif identical?
-- David ----------------------------------------------------- David Huffer, Ph.D. Senior Statistician CSOSA/Washington, DC david.huf...@csosa.gov ----------------------------------------------------- -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of milton ruser Sent: Wednesday, August 26, 2009 12:54 PM To: r-help@r-project.org Subject: [R] changing equal values on matrix by same random number Dear all, I have about 30,000 matrix (512x512), with values from 1 to N. Each value on a matrix represent a habitat patch on my matrix (i.e. my landscape). Non-habitat are stored as ZERO. No I need to change each 1-to-N values for the same random number. Just supose my matrix is: mymat<-matrix(c(1,1,1,0,0,0,0,0,0,0,0, 0,0,0,0,2,2,2,0,0,0,0, 0,0,0,0,2,2,2,0,0,0,0, 3,3,0,0,0,0,0,0,0,4,4, 3,3,0,0,0,0,0,0,0,0,0), nrow=5) I would like that all cells with 1 come to be runif(1,min=0.4, max=0.7), and cells with 2 be replace by another runif(...). I can do it using for(), but it is very time expensive. Any help are welcome. cheers milton [[alternative HTML version deleted]] ______________________________________________ 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. ______________________________________________ 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.
