[GRASS-stats] gstat error

[Edzer Pebesma]

Jarek Jasiewicz wrote:
> Hi
> during trend calculation I recive following error:
>
> R
> library(spgrass6)
> library(gstat)
>
> raster=readRAST6("rzedna")
> p=readVECT6("punkty")
> p at proj4string=raster at proj4string
>
> pg_1=gstat(id="p_1", formula=rzedna~1,data=p, degree=1)
> p_1=predict(pg_1,raster)
> [ordinary or weighted least squares prediction]
>
> "solve.c", line 87: singular matrix in function Usolve()
> Error in predict.gstat(pg_1, raster) : Usolve
There are several situations why this can happen that are hard to
distinguish from the point where the error happens. The most likely in
your case (first order trend surface estimation) is that your data are,
geographically, on a line, i.e. one-dimensionally. Or similary, that you
have less than 3 observations. Is that the case?
--
Edzer
>
>
> my system information:
>
> Ubuntu 8.04
> R 2.8.1
> gstat 0.9.59
> the error have appeared first time on gstat 0.9.49
>
> Errors apears on all my data, even these, where trend was calculated
> some times ago. Commads coming from old data
>
> The error is also reproducible on spearfish dataset with elevation.dem
> and random points generated by v.random
>
> Jarek
> _______________________________________________
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> grass-stats at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/grass-stats

-- 
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.springer.com/978-0-387-78170-9 e.pebesma at wwu.de