On Sat, Dec 24, 2011 at 8:38 AM, William Revelle <[email protected]> wrote: > Dear Matt, Sarah and Rui, > > To answer the original question for creating a symmetric matrix
I read the original question as *only* wanting the complete lower triangle, with diagonal of 1 and 0 in the upper triangle. If your interpretation is correct, there's also this convenience function: library(ecodist) z <- full(v) Sarah > >>>> v<-c(0.33740, 0.26657, 0.23388, 0.23122, 0.21476, 0.20829, 0.20486, >>>> 0.19439, 0.19237, >>>> 0.18633, 0.17298, 0.17174, 0.16822, 0.16480, 0.15027) > > > z<-diag(6) > z[row(z) > col(z)] <- v > z <- z + t(z) > diag(z) <- 0 > >> z > [,1] [,2] [,3] [,4] [,5] [,6] > [1,] 0.00000 0.33740 0.26657 0.23388 0.23122 0.21476 > [2,] 0.33740 0.00000 0.20829 0.20486 0.19439 0.19237 > [3,] 0.26657 0.20829 0.00000 0.18633 0.17298 0.17174 > [4,] 0.23388 0.20486 0.18633 0.00000 0.16822 0.16480 > [5,] 0.23122 0.19439 0.17298 0.16822 0.00000 0.15027 > [6,] 0.21476 0.19237 0.17174 0.16480 0.15027 0.00000 > > > Bill > > > On Dec 24, 2011, at 6:04 AM, Sarah Goslee wrote: > >> Or the slightly shorter: >> >> z<-diag(6) >> z[row(z) > col(z)] <- v >> >> which is what lower.tri() does, >> >> and >> z <- diag(6) >> z[lower.tri(z)] <- v >> >> also works. >> >> Sarah >> >> On Fri, Dec 23, 2011 at 9:31 PM, Rui Barradas <[email protected]> wrote: >>> >>> Matt Considine wrote >>>> >>>> Hi, >>>> I am trying to work with the output of the MINE analysis routine found at >>>> http://www.exploredata.net >>>> >>>> Specifically, I am trying to read the results into a matrix (ideally an >>>> n x n x 6 matrix, but I'll settle right now for getting one column into >>>> a matrix.) >>>> >>>> The problem I have is not knowing how to take what amounts to being one >>>> half of a symmetric matrix - excluding the diagonal - and getting it >>>> into a matrix. I have tried using "lower.tri" as found here >>>> https://stat.ethz.ch/pipermail/r-help/2008-September/174516.html >>>> but it appears to only partially fill in the matrix. My code and an >>>> example of the output is below. Can anyone point me to an example that >>>> shows how to create a matrix with this sort of input? >>>> >>>> Thank you in advance, >>>> Matt >>>> >>>> #v<-newx[,3] >>>> #or, for the sake of this example >>>> v<-c(0.33740, 0.26657, 0.23388, 0.23122, 0.21476, 0.20829, 0.20486, >>>> 0.19439, 0.19237, >>>> 0.18633, 0.17298, 0.17174, 0.16822, 0.16480, 0.15027) >>>> z<-diag(6) >>>> ind <- lower.tri(z) >>>> z[ind] <- t(v)[ind] >>>> >>>> z >>>> [,1] [,2] [,3] [,4] [,5] [,6] >>>> [1,] 1.00000 0.00000 0 0 0 0 >>>> [2,] 0.26657 1.00000 0 0 0 0 >>>> [3,] 0.23388 0.19237 1 0 0 0 >>>> [4,] 0.23122 0.18633 NA 1 0 0 >>>> [5,] 0.21476 0.17298 NA NA 1 0 >>>> [6,] 0.20829 0.17174 NA NA NA 1 >>>> >>>> >>> Hello, >>> >>> Aren't you complicating? >>> >>> In the last line of your code, why use 'v[ind]' if 'ind' indexes the matrix, >>> not the vector? >>> >>> z<-diag(6) >>> ind <- lower.tri(z) >>> z[ind] <- v #This works >>> z >>> >>> Rui Barradas >>> >> >> -- ______________________________________________ [email protected] 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.
