[R] sort matrix by sum of columns

[Petr Pikal]

Hi

order is your friend


On 21 Jun 2006 at 11:38, Albert Vilella wrote:

From:           	Albert Vilella <avilella at gmail.com>
To:             	r help <r-help at stat.math.ethz.ch>
Date sent:      	Wed, 21 Jun 2006 11:38:17 +0100
Subject:        	[R] sort matrix by sum of columns
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> Hi all,
> 
> I would like to know how can I sort the cols of a matrix by the sum of
> their elements.
> 
> 
> a <- matrix(as.integer(rnorm(25,4,2)),10,5)
> colnames(a) = c("alfa","bravo","charlie","delta","echo")

 ord<-order(colSums(a))
 barplot(a[,ord], horiz=TRUE, legend.text=T)

HTH
Petr


>
> 
> I guess I should use colSums, and then rearrange the matrix somehow
> according to the result.
> 
> My idea is to display a "sorted" barplot:
> 
> barplot(a, horiz=TRUE, legend.text=T)
> 
> Thanks in advance,
> 
>     Albert.
> 
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Petr Pikal
petr.pikal at precheza.cz