Re: [R] How to get standard deviation of rows in a matrix

From: Sundar Dorai-Raj <sundar.dorai-raj_at_pdf.com>
Date: Thu 10 Mar 2005 - 07:00:40 EST

Jagarlamudi, Choudary wrote on 3/9/2005 1:49 PM:
> Hi all,
>
> I am trying to find sd of my rows in a matrix and i get column sd inspite of extracting rows.
> I tried to do the sqrt(var(x)) but that did'nt work as well,
>
> Here is my data
>
> genes
> 15 24 63 40
> 25 42 46 35
> 23 53 37 45
> 30 37 50 55
> 40 51 30 48
>
> x<-sd(genes[1:5,])
>
> y<-sqrt(var(genes[1:5,]))
>
> I get 4 sds for the 4 columns instead of 5 sds for my 5 rows.
> Thanks you in advance.
>

This has come up several times in the past and a quick search of the archives would have lead you to:

http://finzi.psych.upenn.edu/R/Rhelp02a/archive/34169.html

HTH,
--sundar



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