Re: [R] delete selecting rows and columns
A one-dimensional delete might be faster:
n - 4000
m - 0.01
matr - matrix(1:(n^2), n, n)
excl_r - sample(n, m*n)
incl_r - setdiff(1:n, excl_r)
excl_c - sample(n, m*n)
incl_c - setdiff(1:n, excl_c)
system.time(matr[-excl_r, -excl_c])
system.time(
{ m4 - matr[outer(incl_r, incl_c, function(i, j) i + n*(j - 1)) ]
dim(m4) - c(length(incl_r), length(incl_c))
} )
Heikki Kaskelma
jastar wrote:
Hi,
I'm working with a big square matrix (15k x 15k) and I have
some trouble.
I want to delete selecting rows and columns.
I'm using something like this:
sel_r=c(15,34,384,985,4302,6213)
sel_c=c(3,151,324,3384,7985,14302)
matrix=matrix[-sel_r,-sel_c]
but it works very slow.
Does anybody know how to make it in faster way?
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Re: [R] delete selecting rows and columns
I mean something like in MATLAB matrix(sel_r,:)=[] jastar wrote: Hi, I'm working with a big square matrix (15k x 15k) and I have some trouble. I want to delete selecting rows and columns. I'm using something like this: sel_r=c(15,34,384,985,4302,6213) sel_c=c(3,151,324,3384,7985,14302) matrix=matrix[-sel_r,-sel_c] but it works very slow. Does anybody know how to make it in faster way? Thank's -- View this message in context: http://www.nabble.com/delete-selecting-rows-and-columns-tf3308726.html#a9327427 Sent from the R help mailing list archive at Nabble.com. __ R-help@stat.math.ethz.ch 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.
[R] delete selecting rows and columns
Hi, I'm working with a big square matrix (15k x 15k) and I have some trouble. I want to deleting selecting rows and columns. I use something like this: sel_r=c(15,34,384,985,4302,6213) sel_c=c(3,151,324,3384,7985,14302) matrix=matrix[-sel_r,-sel_c] but it works very slow. Does anybody know how to make it in faster way? Thank's -- View this message in context: http://www.nabble.com/delete-selecting-rows-and-columns-tf3308726.html#a9203533 Sent from the R help mailing list archive at Nabble.com. __ R-help@stat.math.ethz.ch 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.
