[R] What's going on? (strange standard deviation)

[Roger Peng]

I believe R computes:

sum((x - mean(x))^2) / (N-1)

-roger
_______________________________
UCLA Department of Statistics
rpeng at stat.ucla.edu
http://www.stat.ucla.edu/~rpeng

On Fri, 15 Nov 2002, Matej Cepl wrote:

> I have probably misunderstood something (again :-():
> 
> 	> CEMPLOY<-TEMPLOY[!is.na(TEMPLOY)]
> 	> sum(CEMPLOY^2/length(CEMPLOY))-mean(CEMPLOY)^2
> 	[1] 30877.28
> 	> var(TEMPLOY,na.rm=TRUE)
> 	[1] 30981.25
> 
> Could anybody tell me, what's going on? I suppose that
> 
> 	var=sum(x^2/N)-xbar^2
> 
> or what did I enter wrong?
> 
> 	Thanks
> 
> 		Matej
> 
> -- 
> Matej Cepl, matej at ceplovi.cz,
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