AI-GEOSTATS: Re: polygon kriging

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• What a lot of work when you can just krige the poygon directly! Try polygon kriging with my absolutely free, public domain, kriging game which works with any
Message 1 of 4 , Feb 21, 2004
What a lot of work when you can just krige the poygon
directly!

Try polygon kriging with my absolutely free, public
domain, kriging game which works with any data set in
a suitable format. This Windows based program provides
he kriging equations and weights for the solution, so
http://geoecosse.bizland.co/softwares along with
tutorial data sets.

Isobel

--- Pierre Goovaerts <goovaert@...>
wrote: > Dear Lorenz,
>
> The easiest way to proceed would be to discretize
> using a grid, use stochastic simulation to simulate
> values within
> the polygon, and estimate the block value as the
> arithmetical average
> of these simulated point values.
>
> The advantage is that you can empirically estimate
> the variance of
> your block estimate from the distribution of
> simulated block values.
>
> It would be fairly easy to implement this procedure
> using gslib
> simulation routines. You just need to make sure that
> only the
> grid nodes within the boundaries of the polygon are
> being simulated
> (you can not just simulate a rectangular grid and a
> posteriori
> eliminate the values simulated outside the limits).
> This requires
> a "if statement" inside sgsim or sisim to skip any
> grid node
> falling outside the boundarie (just define a grid of
> indicator values
> that would be one if inside and zero if outside the
> limits of
> the polygon, and read this grid at the beginning of
> the simulation).
>
> Best regards,
>
> Pierre
>
<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
>
> Dr. Pierre Goovaerts
> President of PGeostat, LLC
> Chief Scientist with Biomedware Inc.
> 710 Ridgemont Lane
> Ann Arbor, Michigan, 48103-1535, U.S.A.
>
> E-mail: goovaert@...
> Phone: (734) 668-9900
> Fax: (734) 668-7788
> http://alumni.engin.umich.edu/~goovaert/
>
>
<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
>
> On Fri, 20 Feb 2004, Lorenz Dobler wrote:
>
> > hello list,
> >
> > i would like to assign the principles of
> block-kriging to user defined
> > (=irregular) polygons. some questions about it:
> >
> > 2. is there any software that can do this allready
> ?
> > 3. does anyone of you have practical experiences
> with this approach ?
> > 4. is there a realistic possibility to change
> existing gslib libraries to do
> > kriging with irregular polygons instead of regular
> blocks (problem: finding
> > center [of gravity] for each irregular polygon and
> defining appropriate
> > search neigbourhood !!) ?
> >
> > hope someone can help
> >
> > kind regards
> >
> > Lenz Dobler
> >
> > Universität Münster
> > Institut für Geoinformatik
> > Robert-Koch-Strasse 26-28
> > D-48149 Münster
> >
> > Tel.: 0251/83-30089
> > Fax: 0251/83-39763
> > email: doblerl@...
> >
> >
> > --
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