A=matrix(1:9,3) A[lower.tri(A)] b
On Nov 10, 2006, at 4:50 PM, Davendra Sohal wrote: > Hi all, > Here's an interesting (for me, at least!) problem I came across: > I have a correlation matrix, let's say with 6 variables, A to F, as > column > headings and the same 6 as row headings. > The matrix is filled with correlation coefficients. Therefore, the > diagonal > is all 1's, and each of the two triangles formed by the diagonal > has the > same 15 correlation coefficients. > I need to extract these 15 coefficients from this. I don't want the > 1's and > I don't want redundant values. > I tried converting the matrix to a list, using c(m) and then I'm > stuck. > Does something like b = a[x, x+1:n] exist in R? SAS will do it. > x can be looped to go from 1 to n (n here is 6, of course) and it will > select the required values, but I cannot make it work. > Please help. > Many thanks, > -DS. > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@stat.math.ethz.ch 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@stat.math.ethz.ch 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.