Let me give you a not that efficient one... assume you have read the matrix (named as x) into R:
n=dim(x)[1] y=matrix(0,n,n) for (i in 1:n) y[x[i,1],x[i,2]]=x[i,3] -- View this message in context: http://r.789695.n4.nabble.com/matrix-problem-tp2320193p2320219.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
