Thanks Uwe for your insight. However this could not solve my problem. Actually, I meant to define 'Str' in this way:
> mat <- matrix(c(1,2,0,2,5,0.5,0,0.5,3), 3, 3) > colnames(mat) <- rownames(mat) <- paste("variable", 1:3, sep="") > mat variable1 variable2 variable3 variable1 1 2.0 0.0 variable2 2 5.0 0.5 variable3 0 0.5 3.0 > > Str<- c(paste("variable", 1:4, sep=""), "variable2"); Str [1] "variable1" "variable2" "variable3" "variable4" "variable2" Therefore 'variable2' should appear twice in my modified VCV matrix, which was not there in your suggestion. Is there any better any on how can I do that? or it is really imposable to achieve? Thanks, 2011/4/21 Uwe Ligges <lig...@statistik.tu-dortmund.de>: > > > On 20.04.2011 19:26, Maithula Chandrashekhar wrote: >> >> Dear all, I have special task to expand a given VCV matrix, however >> could not accomplice yet. Let say I have following VCV matrix >> >>> mat<- matrix(c(1,2,0,2,5,0.5,0,0.5,3), 3, 3) >>> colnames(mat)<- rownames(mat)<- paste("variable", 1:3) >>> mat >> >> variable 1 variable 2 variable 3 >> variable 1 1 2.0 0.0 >> variable 2 2 5.0 0.5 >> variable 3 0 0.5 3.0 >> >> Now, say I have a general string vector like this: >> >>> Str<- c(paste("variable", 1:4), "variable2") >>> Str >> >> [1] "variable 1" "variable 2" "variable 3" "variable 4" "variable 2" > > > > If Str is like the printed one above rather than the code example, you can > do: > > mat[Str[Str %in% rownames(mat)], Str[Str %in% colnames(mat)]] > > Uwe Ligges > > > > >> Now according to this string, I want my previous VCV matrix also >> expands. Therefore, as "variable 4" is not there in VCV matrix, so it >> will be ignored. Therefore final VCV matrix will be of order 4, and >> will look like: >> >> variable 1 variable 2 variable 3 variable 2 >> variable 1 1 2 0 2 >> variable 2 2 5 0.5 5 >> variable 3 0 0.5 3 0.5 >> variable 2 2 5 0.5 5 >> >> However, I do not think it is just some straightforward expansion, >> which could be done just by the subsetting mechanism of R. Is there >> any idea on how can I do it for general case? >> >> Thanks for your time, >> >> ______________________________________________ >> 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.