Hi: Here's an example:
m <- as.data.frame(matrix(rnorm(10000), nrow = 100)) dim(m) [1] 100 100 # Assign rownames to rows of m rownames(m) <- paste('A', 1:100, sep = '') # Select a random subset of the rownames vn <- sample(rownames(m), 50) # Subset m by selecting the rownames from vn m2 <- m[rownames(m) %in% vn, ] # Did we get the right ones? identical(sort(vn), sort(rownames(m2))) [1] TRUE HTH, Dennis On Wed, Apr 13, 2011 at 9:13 AM, pankaj borah <pankajborah...@yahoo.co.in>wrote: > I have a matrix M > > > dim(M) > > [1] 30380 561 > > I have another list L contains , that contains some row names of matrix M > str (L) > chr [1:21037] > > Now I want to extract the submatrix subM (21037 , 561) from the > matrix M by matching the rownames (M) to the 21037 rownames o f L > > How do I do that ? > > Thanks and regards, > > Pankaj Barah > > > > > Pankaj Barah Department of Biology > Norwegian University of Science & Technology (NTNU) > Realfagbygget, N-7491 Trondheim, Norway T > [[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. > > [[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.