Replacing values of a matrix with values from corresponding rows of another matrix
This should also work:
mask <- randomized > 0 mask
[,1] [,2] [,3] [,4] [,5] [,6] [1,] FALSE FALSE TRUE FALSE FALSE TRUE [2,] TRUE TRUE FALSE TRUE TRUE TRUE [3,] FALSE TRUE TRUE FALSE FALSE TRUE [4,] TRUE TRUE FALSE TRUE FALSE TRUE
randomized[mask] <- original[mask] randomized
[,1] [,2] [,3] [,4] [,5] [,6] [1,] 0 0 4 0 0 1 [2,] 2 2 0 1 0 2 [3,] 0 5 0 0 0 1 [4,] 3 1 0 5 0 4 ------------------------------------- David L Carlson Associate Professor of Anthropology Texas A&M University College Station, TX 77840-4352 -----Original Message----- From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Laura Cisneros Sent: Monday, July 15, 2013 8:31 AM To: Blaser Nello Cc: r-help at r-project.org Subject: Re: [R] Replacing values of a matrix with values from corresponding rows of another matrix Great! Thank you, Nello. It works on my larger matrices. On Mon, Jul 15, 2013 at 2:40 AM, Blaser Nello
<nblaser at ispm.unibe.ch> wrote:
For small matrix you could use a for-loop.
for (i in 1:nrow(randomized)){
randomized[i,randomized[i,]!=0] <-
sample(original[i,original[i,]!=0])
}
randomized
If you have a larger matrix sapply is probably faster
randomized <- t(sapply(1:nrow(randomized), function(i) {
randomized[i,randomized[i,]!=0] <-
sample(original[i,original[i,]!=0])
randomized[i,] })) randomized Best, Nello -----Original Message----- From: r-help-bounces at r-project.org
[mailto:r-help-bounces at r-project.org]
On Behalf Of Laura Cisneros Sent: Montag, 15. Juli 2013 03:09 To: r-help at r-project.org Subject: [R] Replacing values of a matrix with values from
corresponding
rows of another matrix Hello all, I have been trying to figure out how to replace non-zero values of
a
matrix with non-zero values from corresponding rows from another
matrix.
More specifically, let say we have the following original matrix: original <-
matrix(c(0,0,4,0,0,1,2,2,12,1,0,2,0,5,0,0,10,1,3,1,0,5,0,4),byrow=TR UE,nrow=4,ncol=6)
original
[,1] [,2] [,3] [,4] [,5] [,6] [1,] 0 0 4 0 0 1 [2,] 2 2 12 1 0 2 [3,] 0 5 0 0 10 1 [4,] 3 1 0 5 0 4 And we randomize this matrix such that the total of occurrences of non-zero values in each row and column are maintained in the
randomized
matrix: randomized <-
matrix(c(0,0,12,0,0,1,2,2,0,5,10,2,0,1,4,0,0,1,3,5,0,1,0,4),byrow=TR UE,nrow=4,ncol=6)
randomized
[,1] [,2] [,3] [,4] [,5] [,6] [1,] 0 0 12 0 0 1 [2,] 2 2 0 5 10 2 [3,] 0 1 4 0 0 1 [4,] 3 5 0 1 0 4 What I would like to do now is replace (in a random fashion) the
non-zero
values in each row of the randomized matrix using the non-zero
values from
the corresponding rows in the original matrix. For example, for
row 1 I
would like to randomly replace 12 and 1 (from the randomized
matrix) with 4
and 1 (from the original matrix). Then do this for each row. Any suggestions on how I may be able to accomplish this would be
greatly
appreciated. Laura -- Laura Cisneros, Doctoral Candidate Dept. of Ecology and Evolutionary Biology University of
Connecticut
75 N. Eagleville Road, U-3043
Storrs, CT 06269-3043
Tel: (860) 486-1772
Fax: (860) 486-5488
Alternative Email: laura.cisneros at uconn.edu
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______________________________________________ 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.
Laura Cisneros, Doctoral Candidate Dept. of Ecology and Evolutionary Biology University of Connecticut 75 N. Eagleville Road, U-3043 Storrs, CT 06269-3043 Tel: (860) 486-1772 Fax: (860) 486-5488 Alternative Email: laura.cisneros at uconn.edu [[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.