Edzer Pebesma pisze:
Jarek Jasiewicz wrote:Hi during trend calculation I recive following error: R library(spgrass6) library(gstat) raster=readRAST6("rzedna") p=readVECT6("punkty") p...@proj4string=raster@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) : UsolveThere 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
Thanks for answer, but none of that case. Tt is regular data file with 200 random observations generated with v.random in GRASS and stored as SpatialPointDataFrame. before I posted to the list I had tried to reproduce it on my archive data with archive scripts (which worked in older R compilation) and it ALWAYS fail (on every data I tested).
In general, the possible problem on my side coud be that I (experientally) installed R from CRAN ubuntu repository instead to compile from source. The ubuntu CRAN-R packages do not include lapack. This is the only difference I noticed.
If you need I can send you sample R file (is small, no more than 2MB) Jarek
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 _______________________________________________ grass-stats mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-stats
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