This is not an answer to your question, but I have used SparseM
package to represent large travel time matrices efficiently.
?as.matrix.ssr
if the traveltime matrix is symmetric.
On 9 Nov 2009, at 5:24PM, Hongwei Dong wrote:
Hi, R users,
I'm trying to transform a matrix A into B (see below). Anyone knows
how to
do it in R? Thanks.
Matrix A (zone to zone travel time)
zone z1 z2 z3 z1 0 2.9 4.3 z2 2.9 0 2.5 z3 4.3 2.5 0
B:
from to time z1 z1 0 z1 z2 2.9 z1 z3 4.3 z2 z1 2.9 z2 z2 0 z2 z3 2.5
z3 z1
4.3 z3 z2 2.5 z3 z3 0
The real matrix I have is much larger, with more than 2000 zones.
But I
think it should be the same thing if I can transform A into B.
Thanks.
Garry
[[alternative HTML version deleted]]
______________________________________________
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.
______________________________________________
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.
