Re: [R] matrix

From: Peter Langfelder <peter.langfelder_at_gmail.com>
Date: Tue, 26 Apr 2011 14:35:14 -0700

On Tue, Apr 26, 2011 at 2:28 PM, Val <valkremk_at_gmail.com> wrote:
> Hi all,
>
> Assume I have a matrix
> xv=  [1 0 0 0 0 12,
>      0 1 0 0 0 10,
>  *    0 0 1 0 0 -9,*
>      0 0 0 1 0 20,
>    *  0 0 0 0 1 -5]*
>
> if the last column of "xv"  less than  0 then I want to set zero the entire
> row.
> The desired output looks like the following. In this case row 3 and row 5
> are set zero.
>
>    [ 1 0 0 0 0 12,
>      0 1 0 0 0 10,
>     * 0 0 0 0 0 0,*
>      0 0 0 1 0 20,
>    *  0 0 0 0 0 0*]
>
> I used ifelse command but did not work
>
> Is there another command to do that?

Yes.

nc = ncol(xv)
result = xv;
result[ xv[, nc] <0, ] = 0

HTH, Peter



R-help_at_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. Received on Tue 26 Apr 2011 - 21:38:47 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Tue 26 Apr 2011 - 22:10:33 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive