[R-sig-Geo] gstat error

Edzer Pebesma edzer.pebesma at uni-muenster.de
Sat Oct 15 17:11:29 CEST 2011


As you gave practically no information besides the error message, why 
don't you simply try that.

Another possible cause is using a Gaussian variogram model with zero nugget.



On 10/15/2011 04:48 PM, Sandeep Patil wrote:
> I did check the data once again and did not find any such points .
> Should i remove points that are very close to each other i.e
> replace them with a single point ?
>
> On Sat, Oct 15, 2011 at 4:14 AM, Edzer Pebesma
> <edzer.pebesma at uni-muenster.de <mailto:edzer.pebesma at uni-muenster.de>>
> wrote:
>
>     The most common cause is that you have multiple observations at
>     single locations. You can use function zerodist to figure out
>     whether this is the case.
>
>
>     On 10/14/2011 06:11 PM, Sandeep Patil wrote:
>
>         Hello
>
>         I am running a Kriging cross validation in Automap. I get the
>         following
>         error
>
>
>         "chfactor.c", line 130: singular matrix in function LDLfactor()
>
>         I did check out the troubleshooting part of gstat manual which
>
>         suggested two possible reasons
>
>
>
>         during simulation, when an observation falls almost exactly at a
>         simu-
>         lation location. Solution: increase the value of zero
>
>         when two observations occur at identical location occur and
>         noaverage
>         or average=0 was dened in a data denition. Solution: remove the
>         noaverage, or add average=1
>
>
>         Can someone elaborate what exactly is to be done in the above
>         two options
>         as i am finding it a bit cryptic.
>
>
>     --
>     Edzer Pebesma
>     Institute for Geoinformatics (ifgi), University of Münster
>     Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251
>     8333081, Fax: +49 251 8339763 <tel:%2B49%20251%208339763>
>     http://ifgi.uni-muenster.de
>     http://www.52north.org/__geostatistics
>     <http://www.52north.org/geostatistics> e.pebesma at wwu.de
>     <mailto:e.pebesma at wwu.de>
>
>     _________________________________________________
>     R-sig-Geo mailing list
>     R-sig-Geo at r-project.org <mailto:R-sig-Geo at r-project.org>
>     https://stat.ethz.ch/mailman/__listinfo/r-sig-geo
>     <https://stat.ethz.ch/mailman/listinfo/r-sig-geo>
>
>
>
>
> --
> Sandeep R Patil
> Graduate Student
> M.S (Hydrological Sciences)
>

-- 
Edzer Pebesma
Institute for Geoinformatics (ifgi), University of Münster
Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251
8333081, Fax: +49 251 8339763  http://ifgi.uni-muenster.de
http://www.52north.org/geostatistics      e.pebesma at wwu.de



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