[GRASSLIST:3629] more r.mapcalc troubles
werchowyna at pf.pl
Tue Jun 8 17:46:39 EDT 2004
Thanks for the support so far! Here is one more strange thing in r.mapcalc I
encountered during my low-level computing :).
I'm using Grass 5.03 installed from the binaries from the Grass www.
I made a following raster for my vignetting correction purposes:
r.mapcalc 'kor_lx = ( 1218.01 / ( sqrt( (double(x()) - 941.0) ^2.0 +
(double(y()) - 928.0)^2.0) ^2.0 + 1218.01^2.0) ) ^4.0'
the value range for 'kor_lx' file is (read from the color file in the 'colr'
0.00000000000002026206628416476 - 0.000000000000454355718931865126
I checked if r.mapcalc hadles the 'kor_lx''s values properly by doing:
the data range in the 'colr' file for 'copy' was DIFFERENT (the min value is
higher than in 'kor_lx'):
0.000000000000028123670807620238 - 0.000000000000454355718931865126
the difference is:
0.000000000000028123670807620238 - 0.00000000000002026206628416476
The difference beetween 'kor_lx' and the 'copy' is very well visible on the
attached window dump. It's a "copy" partly drawn over the "kor_lx" (caught
in the 1/4 of drawing on Grass monitor - see the upper 1/4 of the picture).
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