On Nov 20, 2007 7:04 PM, Moshe Olshansky <[EMAIL PROTECTED]> wrote: > You can do the following: > > set1 <- Matrix1[,1] > set2 <- Matrix2[,1] > common <- intersect(set1,set2) > ind1 <- which(set1 %in% common) > ind2 <- which(set2 %in% common) > > A1 <- Matrix1[ind1,-1] > A2 <- Matrix2[ind2,-1]
Ok, this far. > > and if you wish, > > rownames(A1) <- common > rownames(A2) <- common The latter two are not guaranteed to be correct, because they assume that 'ind1' and 'ind2' also reorders the rows according to 'common', but this far you only used set operations. Try with: Matrix1 <- matrix(letters[1:5], nrow=5, ncol=2) Matrix2 <- matrix(letters[5:1], nrow=5, ncol=2) This is best understood if you remove the which():es and just keep the logical vectors. Instead, match() will order the indices according to the target vector. Make sure to deal with missing values. Example: idx1 <- na.omit(match(set1, common)) idx2 <- na.omit(match(set2, common)) /H > > > --- "C.S. Liu" <[EMAIL PROTECTED]> wrote: > > > Dear list, > > > > I have two martix like these, each rows with > > name in the matrix. > > > > I try to select rows with identical name from > > two matrix and calculate their correlation. > > > > Matrix1: > > 2-Sep 9 5.5 1 7.18 10.0 8 > > 139.45 > > 2-Sep 7 4.9 15 8.22 61.68 9 > > 123.62 > > 4-Sep > > 5-Sep > > AAMP > > A2M > > A2M > > . > > . > > . > > > > Matrix2: > > > > 2-Sep 4 7 1 6.8 12 8 19.4 > > 2-Sep 2 8 15 2.2 6.8 12 13.2 > > 4-Sep > > AAMP > > AAMP > > ABCA5 > > A2M > > A2M > > > > I try to select rows with identical name from two > > matrix and calculate their correlation. > > > > However, I got trouble when loading these two matrix > > into R as header=TRUE. > > > > So I use header=FLASE and these name become > > character in the first column. > > > > How do I extract the first column of matrix 1 and > > compare to the first column of matrix 2? > > > > And if they are identical I compute their > > correlation? > > > > > > SIncerely yours, > > Chiahsin Liu > > > > [[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.
