On 10/10/07, Birgit Lemcke <[EMAIL PROTECTED]> wrote: > Hello and sorry that I still haven´t found a solution for my problem. > > I need to extract the lower and upper triangle from a square matrix > including the diagonal. This diagonal is not zero in that special case. > I tried with as.dist > > w<-as.dist(w, diag = TRUE) > > w > 1 2 3 4 5 > 1 0 > 2 2 0 > 3 3 8 0 > 4 4 9 14 0 > 5 5 10 15 20 0 > > but found no way to keep the diagonal that is in the matrix. > > I also tried this but as I expected it makes no difference: > > w<-matrix(1:25, ncol=5, nrow=5) > > upperTriangle(w)<-NA > > w > [,1] [,2] [,3] [,4] [,5] > [1,] 1 NA NA NA NA > [2,] 2 7 NA NA NA > [3,] 3 8 13 NA NA > [4,] 4 9 14 19 NA > [5,] 5 10 15 20 25 > > w<-as.dist(w, diag = TRUE) > > w > 1 2 3 4 5 > 1 0 > 2 2 0 > 3 3 8 0 > 4 4 9 14 0 > 5 5 10 15 20 0 > > Is there perhaps a possibility to give the diagonal as a vector > within as.dist? > > I would be glad if somebody could help me. > > Greetings > > Birgit > > Birgit Lemcke > Institut für Systematische Botanik > Zollikerstrasse 107 > CH-8008 Zürich > Switzerland > Ph: +41 (0)44 634 8351 > [EMAIL PROTECTED] >
What do you want to do with the lower triangle matrix? A distance matrix must be zero on the diagonal, since dist(a,a)==0 for all a, so it cannot be distances that you measure. best, Gustaf -- Gustaf Rydevik, M.Sci. tel: +46(0)703 051 451 address:Essingetorget 40,112 66 Stockholm, SE skype:gustaf_rydevik ______________________________________________ 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.
