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Compliments.
I find Gstat of great interest;it is very useful for me to
prepare my tesis.
I need to spatialize rainfall data in the Sahell
region.
Unlukyly I cannot manage to get the predictions with kriging
done.
My original data are stored in an arcinfo point cover;from
that cover I made a grid with POINTGRID, setting the background value to 0;then
I changed the value of the points in the grid that hold the precipition
data to -1 (value that I used in as no data in g-stat).I used this grid,
converted in ASCII file with GRIDASCII, as the mask map to
obtain predictions.
Then I made a point cover from the Grid with GRIDPOINT, and
using UNGENERATE I finally got the imput data for gstat.
The data are in Lambert Azimuth Equal Area Proiection and the
cell size is 999.88 meters.
I get the following error message:
To get the input data in Gstat I used the Ungenerate command
is I made a grid
cant'solve a problem:
"solve.c", line 87: singular matrix in function
Usolve()
"lufactor.c", line 207: singular matrix in function
m_inverse()
gstat caught an error that occurred in the matrix
library,
the reason for it was: singular matrix HINT: The most frequent occasion for this error is when two
(or more) da
ta points have identical locations. The way to solve it is to add the word `average' (without quotes) to the data definition. If this does not resolve the problem, it may be possible that nearly identical data point locations are the cause. Remove them manually, or set the
default value
of the variable `zero' to a larger value (but check the manual for a suitab le value and the side effects this may have!) gstat: matrix library error: singular matrix
My original command file is:
data(aap):'cl528lamj.txt',x=1,y=2,v=4,X=y,radius=300000,vdist,average,mv=-1;
variogram(aap): 29599
Gau(284898);
mask:'st532lg2n.txt';
predictions(aap):'aapclpr.txt';
variances(aap):'aapclvr.txt';
set cutoff = 1e+006;
set fit = 1; set tol_hor = 30; set width = 104311; Changing the zero value and zero distance às follows did not
help:
set zero=1.0e-7;
set zero_dist=2; Can you help me?
Is the use of the map wrong?It is actually a bit unclear in
the manual.
I am stuck.
Hoping in your reply,
I thank you in advance.
Manuel
Cuccillato |