big edge list to adjacency matrix
Hello, The following is a bit convoluted but will do it. dat <- read.table(text = " a1 b1 1 a2 b2 2 a3 b3 3 a1 b1 4 a3 b1 5 ") xtabs(V3 ~ V1 + V2, data = aggregate(V3 ~ V1 + V2, data = dat, FUN = max)) Hope this helps, Rui Barradas Em 12-03-2013 21:45, avinash sahu escreveu:
I have huge list of edges with weights.
a1 b1 w1
a2 b2 w2
a3 b3 w3
a1 b1 w4
a3 b1 w5
I have to convert it into 2 dim matrix
b1 b2 b3
a1 max(w1,w4) 0 0
a2 0 w2 0
a3 w5 0 w3
if edges repeated take the maximum weights. How do this efficiently without
using for loop? Any idea.
thanks
Avi
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