On May 3, 2011, at 4:24 AM, Uwe Ligges wrote:
On 03.05.2011 13:16, nuncio m wrote:
Hi list,
I have a matrix with all elements of some columns are zeroes. Is it
possible to remove these columns:
Xnew <- X[ , as.logical(colSums(X)), drop=FALSE]
A counter-example:
X <- matrix(c(1,1,1,-1,0,1,1,1,1),3)
A fix:
> Xnew <- X[ , as.logical(colSums(abs(X))), drop=FALSE]
> Xnew
[,1] [,2] [,3]
[1,] 1 -1 1
[2,] 1 0 1
[3,] 1 1 1
Uwe Ligges
and create a new matrix
nuncio
David Winsemius, MD
Heritage Laboratories
West Hartford, CT
______________________________________________
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.
