How to transform the Matrix into the way I want it ???
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]]
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