portnoy at supereva.it
2007-Feb-07 13:43 UTC
[R] sorting a matrix by a different colnames order
Hi R users,
I would like to know how to sort a matrix according a different order of
colnames (or rownames) ,e.g.,
mx = matrix(rnorm(1:20),5,4)
colnames(mx) = letters[1:4]
rownames(mx) = letters[1:5]
mx
a b c d
a 0.02362598 -0.7033460 0.8106089 -1.03456219
b -0.45021522 -1.5769522 0.1770634 0.27997249
c 1.34732392 0.2956623 2.0027231 -0.85321627
d 0.82314457 1.2698347 -0.5468151 0.05806375
e -0.18668401 -0.4210383 0.6263465 -0.18889031
(new.col.names = sample(letters[1:4]))
[1] "a" "b" "d" "c"
so the new matrix has to be ordered according the new.col.names,i.e.,
a b d c
a 0.02362598 -0.7033460 -1.03456219 0.8106089
b -0.45021522 -1.5769522 0.27997249 0.1770634
c 1.34732392 0.2956623 -0.85321627 2.0027231
d 0.82314457 1.2698347 0.05806375 -0.5468151
e -0.18668401 -0.4210383 -0.18889031 0.6263465
Hope this is not a "basic question"
Thank you for your help.
Paolo
> mx = matrix(rnorm(1:20),5,4) > colnames(mx) = letters[1:4] > rownames(mx) = letters[1:5] > mxa b c d a -0.6264538 -0.8204684 1.5117812 -0.04493361 b 0.1836433 0.4874291 0.3898432 -0.01619026 c -0.8356286 0.7383247 -0.6212406 0.94383621 d 1.5952808 0.5757814 -2.2146999 0.82122120 e 0.3295078 -0.3053884 1.1249309 0.59390132> (new.col.names = sample(letters[1:4]))[1] "d" "b" "c" "a"> mx[, new.col.names]d b c a a -0.04493361 -0.8204684 1.5117812 -0.6264538 b -0.01619026 0.4874291 0.3898432 0.1836433 c 0.94383621 0.7383247 -0.6212406 -0.8356286 d 0.82122120 0.5757814 -2.2146999 1.5952808 e 0.59390132 -0.3053884 1.1249309 0.3295078>On 2/7/07, portnoy at supereva.it <portnoy at supereva.it> wrote:> Hi R users, > I would like to know how to sort a matrix according a different order of > colnames (or rownames) ,e.g., > mx = matrix(rnorm(1:20),5,4) > colnames(mx) = letters[1:4] > rownames(mx) = letters[1:5] > mx > a b c d > a 0.02362598 -0.7033460 0.8106089 -1.03456219 > b -0.45021522 -1.5769522 0.1770634 0.27997249 > c 1.34732392 0.2956623 2.0027231 -0.85321627 > d 0.82314457 1.2698347 -0.5468151 0.05806375 > e -0.18668401 -0.4210383 0.6263465 -0.18889031 > > (new.col.names = sample(letters[1:4])) > [1] "a" "b" "d" "c" > > so the new matrix has to be ordered according the new.col.names,i.e., > a b d c > a 0.02362598 -0.7033460 -1.03456219 0.8106089 > b -0.45021522 -1.5769522 0.27997249 0.1770634 > c 1.34732392 0.2956623 -0.85321627 2.0027231 > d 0.82314457 1.2698347 0.05806375 -0.5468151 > e -0.18668401 -0.4210383 -0.18889031 0.6263465 > > Hope this is not a "basic question" > > Thank you for your help. > > Paolo > > ______________________________________________ > 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 > and provide commented, minimal, self-contained, reproducible code. >-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve?