Hi Javier,
The sill of the semivariogram, if it exists, is usually
not equal to the sample variance, see Journel and Huijbregt's
book p. 67 or the following reference:
Barnes, R.J. 1991. The variogram sill and the sample variance.
Mathematical Geology, 23: 673-678.
Cheers,
Pierre
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On Sun, 21 Apr 2002, Javier wrote:
> Hi all;
> I guess this is a very simple question:
> Is it supposed the sill is always the variance of the set of data?
> If so, is it always better to perform a manual tunning, (after the inicial automatic
>adjusment of a semivariogram establish a sill -say in gstat-), to force it to reach
>the variance of the data?
>
> Thanks and regards
> ----------------
> Javier Garc�a
>
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