[R] Standard Deviation of a matrix

Paul Hiemstra paul.hiemstra at knmi.nl
Tue Aug 2 14:06:54 CEST 2011


 Hi!

The sample below should give you what you want:

M = matrix(runif(100), 10, 10)
sd(as.numeric(M))

So the as.numeric command is the key. It transforms the matrix to a 1D
vector. Or alternatively without using as.numeric:

M = matrix(runif(100), 10, 10)
M
dim(M) = 100
M
sd(M)

Here I use the dim command to set the dimensions to a vector of 100 long.

cheers,
Paul

On 08/02/2011 11:07 AM, chakri wrote:
> Hello,
>
> My R knowledge could not take me any further, so this request !
>
> I have a matrix of dimensions (1185 X 1185). I want to calculate standard
> deviation of entire matrix. 
> sd function of {stats} calculates standard deviation for each row/column,
> giving 1 X 1185 matrix as result. I would like to have 1 X 1 matrix as
> result.
>
> Any ideas, how to do this ?
>
> TIA
> Chakri 
>
> --
> View this message in context: http://r.789695.n4.nabble.com/Standard-Deviation-of-a-matrix-tp3711991p3711991.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org 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.


-- 
Paul Hiemstra, Ph.D.
Global Climate Division
Royal Netherlands Meteorological Institute (KNMI)
Wilhelminalaan 10 | 3732 GK | De Bilt | Kamer B 3.39
P.O. Box 201 | 3730 AE | De Bilt
tel: +31 30 2206 494

http://intamap.geo.uu.nl/~paul
http://nl.linkedin.com/pub/paul-hiemstra/20/30b/770



More information about the R-help mailing list