On Fri, Apr 29, 2011 at 07:44:59AM -0700, Alaios wrote: > Thanks a lot. > I finally used > > M2 <- M > M2[M < thresh] <- 0 > M2[M >= thresh] <- 1 > > as I noticed that this one line > > M2 <- as.numeric( M[] < thresh ) > vectorizes my matrix.
Hi. This may be avoided, for example M2 <- M M2[, ] <- as.numeric(M >= thresh) or array(as.numeric(M >= thresh), dim=dim(M)) > One more question I have two matrices that only differ slightly. What will be > the easiest way to compare and find the cells that are not the same? If A and B are matrices of the same dimension, then A == B is a logical matrix with TRUE entires for positions, where A and B match exactly. abs(A - B) <= eps is a logical matrix with TRUE entires for positions, where A and B differ at most by eps. If you want to get only one logical result, then use all(A == B) for exact equality and all(abs(A - B) <= eps) for approximate equality of all entries. See also ?all.equal, which uses the relative error, not absolute difference. Hope this helps. Petr Savicky. ______________________________________________ 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.
