R help - Apr 2011 - matrix

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?

Thanks in advance
\

	[[alternative HTML version deleted]]

Try this:

replace(m, m[,ncol(m)] < 0, 0)

On Tue, Apr 26, 2011 at 6:28 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?
>
> Thanks in advance
> \
>
> ? ? ? ?[[alternative HTML version deleted]]
>
> ______________________________________________
> 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.
>


-- 
Henrique Dallazuanna
Curitiba-Paran?-Brasil
25? 25' 40" S 49? 16' 22" O

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