Hi,
You could also do: library(reshape2) dcast(dat,V1~V2,value.var="V3",max,fill=0) # V1 b1 b2 b3 #1 a1 4 0 0 #2 a2 0 2 0 #3 a3 5 0 3 A.K. ----- Original Message ----- From: Rui Barradas <ruipbarra...@sapo.pt> To: avinash sahu <avinash.s...@gmail.com> Cc: r-help@r-project.org Sent: Tuesday, March 12, 2013 7:10 PM Subject: Re: [R] 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 > > [[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. ______________________________________________ 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.
