Re: [Bug-gsl] gsl_stats_sd_m ???

[Brian Gough]

At Tue, 1 Jul 2008 09:19:33 +0430 (IRDT),
Mehdi Esteghamatian wrote:
> This is Mehdi Stegamatian. I am student of "Artificial Intelligence" in
> Shiraz University. It is about 6 mounts that I am using GSL. I found
> something which appeared to me as a bug. GSL calculates standard deviation
> of single number equal to nan! Which sounds a bit vired to me. I am not a
> statistician but according to my knowledge the value is zero.
> I included the sample code? Could you tell me what is going on?

Hello,

We calculate the variance with a factor of 1/(N-1) to give an
unbiased estimate of the variance.  

See the "Statistics" chapter of the GSL Reference manual for the
complete definitions of the different functions.  If you want to
compute it with 1/N there are functions which do that.

-- 
Brian Gough

GNU Scientific Library -
http://www.gnu.org/software/gsl/