The simple kriging weights are not constrained in any

way, either in sum or in sign.

Solving the simple kriging system gives a regression

equation which 'best' predicts the value at the

specified location. This is usually adjusted to be

unbiassed by applying the 'rest' (1 - sum of weights)

to the global average.

I have had cases where the simple kriging weights

added up to 2.

Isobel

http://geoecosse.bizland.com

--- Andreas Dominik Cullmann <acullma@...> wrote:

> Hi all,

to

> the simple kriging weights do not sum to a constant.

>

>

> From Olea (1999): 'Geostatistics for engineers and

> earth scientists',

> Kluwer, Boston, p.60:

> '(c) The possibility of having negative weights

> implies that the

> estimate is not confined to the data interval;...'

>

> To me, this sounds like if the sum of the simple

> kriging weights

> is resticted to some interval, especially since I've

> never seen

> any sum of weights not in [0,1].

> Does anybody know any hint, evidence or proof of

> such a

> restriction?

>

> Thanks a lot.

>

>

> ---------------------------------

> Andreas Dominik Cullmann

> Institut fuer forstliche Biometrie und Informatik

> Buesgenweg 4

> 37077 Goettingen

> Germany

> Tel: ++49-551-39-3462

>

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