[R] sort (all columns of) a matrix
Daniel Malter
daniel at umd.edu
Thu Oct 8 20:32:21 CEST 2009
I assume you want to sort the whole dataset (matrix) by ordering one column
in ascending order (and order all other columns appropriately).
a<-matrix(a<-c(1,3,4,6,6,4,6,56,4,64,86,39,4,2),length(a),2)
a
#sort by first column
a[order(a[,1]),]
#sort by second column
a[order(a[,2]),]
#both give the same result here because the columns are identical
HTH,
Daniel
-------------------------
cuncta stricte discussurus
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Von: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] Im
Auftrag von Kajan Saied
Gesendet: Thursday, October 08, 2009 12:51 PM
An: r-help at r-project.org
Betreff: [R] sort (all columns of) a matrix
Dear R-Help Team,
I have been trying to sort (all columns of) a matrix:
> a<-matrix(a<-c(1,3,4,6,6,4,6,56,4,64,86,39,4,2),length(a),2)
> a
[,1] [,2]
[1,] 1 1
[2,] 3 3
[3,] 4 4
[4,] 6 6
[5,] 6 6
[6,] 4 4
[7,] 6 6
[8,] 56 56
[9,] 4 4
[10,] 64 64
[11,] 86 86
[12,] 39 39
[13,] 4 4
[14,] 2 2
>
I would like to have the matrix sorted and the output should again be *a
matrix* with nrow=length(a) and ncol=2 just like (a) but only sorted.
Whatever I try (be it sort(), order()...) I receive a vector of
length(a)*2...
Could you please help me?
Best regards,
kajan
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