Liaw, Andy
2005-Feb-17 15:00 UTC
[R] Converting a list to a matrix - I still don't think I hav e it right
Try: mat <- do.call("rbind", l2) Not sure if the names get put into the rownames automatically, but if not, just do: rownames(mat) <- names(l2) Andy> From: michael watson (IAH-C) > > Hi > > We have touched on this before, but I don't think I quite got > it right. > > So I have a list, each element of which is a a vector of 2 numbers: > > > l2 > $cat000_a01 > [1] 0.3429944 4.5138244 > > $cat000_a02 > [1] 0.1929336 4.3064944 > > $cat000_a03 > [1] -0.2607796 4.1551591 > > What I actually want to convert this into is a matrix with the names > (cat000_a01 etc) as row names, the first element of each of > the vectors > forming the first column of the new matrix, and the second element of > each of the vectors forming the second column: > > cat000_a01 0.3429944 4.5138244 > cat000_a02 0.1929336 4.3064944 > cat000_a03 -0.2607796 4.1551591 > > What was suggested on the list last time was > matrix(unlist(mylist),nrow=length(mylist)). But if I do this I get: > > > matrix(unlist(l2),nrow=length(l2)) > [,1] [,2] > [1,] 0.3429944 4.3064944 > [2,] 4.5138244 -0.2607796 > [3,] 0.1929336 4.1551591 > > Which is not what I want. Here, the second element of the > first vector > in my list has gone into the first column of the new matrix, > and that's > not what I want at all. > > Any more help would be appreciated. > > Thanks > Mick > > ______________________________________________ > R-help at 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 > >
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