Providing a reproducible example is a good idea, but what about this:
> A <- matrix(1:20, nrow=4)
> MASK <- matrix(FALSE, nrow=4, ncol=5)
> MASK[2:3, 1:3] <- TRUE
> MASK
[,1] [,2] [,3] [,4] [,5]
[1,] FALSE FALSE FALSE FALSE FALSE
[2,] TRUE TRUE TRUE FALSE FALSE
[3,] TRUE TRUE TRUE FALSE FALSE
[4,] FALSE FALSE FALSE FALSE FALSE
> A[rowSums(MASK) > 0, colSums(MASK) > 0]
[,1] [,2] [,3]
[1,] 2 6 10
[2,] 3 7 11
Alternatively, you could take the vector returned by:
> A[MASK]
[1] 2 3 6 7 10 11
and put it back into matrix format.
Sarah
On Tue, Jun 12, 2012 at 12:44 PM, Michael <[email protected]> wrote:
> Hi all,
>
> Lets say I have a matrix A which is m x n.
>
> I also have a mask matrix MASK which is m x n with values in T/F, where T
> values make a sub-matrix in regutangular shape...
>
> I applied B=A[MASK] and it didn't work as expected...
>
> Any thoughts?
--
Sarah Goslee
http://www.functionaldiversity.org
______________________________________________
[email protected] 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.
