On 09/20/2010 06:18 PM, nunosousa84 wrote:
Here are the results:
http://osgeo-org.1803224.n2.nabble.com/file/n5551158/cleanresult.jpeg
Well im not sure but at first glance doesnt seem to have much relation. This
vector points layer that appear after runing the v.clean command shows also
possible duplication of lines or just crossing lines? I have made a zoom to
the vector lines where those 11 vector points are located and dont seem to
recognize the problem.
If digitizing was done without snapping, then there might be very small
overshoots which v.clean has caught. But you're right that there doesn't
seem to be any connection to the black spots in the shaded relief. In
any case you might recreate the DEM using r.surf.contour with the
cleaned vector contour layer.
As for the null values in the shaded relief, they should not be there.
I can't see, in the r.shaded.relief script any way for NULL values to
sneak in other than from cells with slope of 90 deg. Someone with a
better understanding of the r.shaded.relief algorithm will have to pitch
in...
If you want to continue with this, perhaps run r.slope.aspect on the DEM
to get a slope raster, and check (r.univar again) what the min and max
slope values are, and where, if any, you are getting 90° slope.
--
Micha
Here goes the comparation results for both r.surf.contour layer and shaded
relief layer, using the r.univar query:
(surfcontour layer)
total null and non-null cells: 2256660
total null cells: 0
Of the non-null cells:
----------------------
n: 2256660
minimum: 430
maximum: 760
range: 330
mean: 541.46
mean of absolute values: 541.46
standard deviation: 66.726
variance: 4452.36
variation coefficient: 12.3234 %
sum: 1221890343.312690258
---------------------------//------------------------
(shadedrelief layer)
total null and non-null cells: 2256660
total null cells: 6164
Of the non-null cells:
----------------------
n: 2250496
minimum: -75.1119
maximum: 100
range: 175.112
mean: 42.1701
mean of absolute values: 48.816
standard deviation: 35.304
variance: 1246.37
variation coefficient: 83.718 %
sum: 94903752.6220222563
It seems only when i run the command shaded relief that null cells appears.
Is it normal?
--
Micha Silver
Arava Development Co. +972-52-3665918
http://www.surfaces.co.il
_______________________________________________
grass-user mailing list
[email protected]
http://lists.osgeo.org/mailman/listinfo/grass-user
