On 06/08/2010 05:39 PM, Rebecca Bennett wrote:
Dear all,
I'm having some trouble copying the values from a raster image
(Dartmoor1) to a series of vector points (Contour_points - created
from a contour vector map). When I try to use v.what.rast I get the
following error:
v.what.rast vector=contour_poi...@permanent raster=dartmo...@permanent
layer=1 column=level
More points (644858) of category 1, value set to 'NULL'
1 categories loaded from table
1 categories loaded from vector
0 categories from vector missing in table
1 duplicate categories in vector
1 records updated
0 update errors
Looks like all the points in Contour_points have the same cat value.
Check this with:
v.category Contour_points opt=report
You can add new separate cat values for each point like this:
v.category Contour_points opt=del out=Contour_points_tmp
v.category Contour_points_tmp opt=add out=Contour_points_cats
(get rid of the tmp vector: g.remove vect=Contour_points_tmp)
Now check:
v.category Contour_points_cats opt=report
Next setup a column for the rast values:
v.db.addcol Contour_points_cats col="rast_value double"
(Is your raster an integer or float raster??)
And now you should be able to get the raster values into the points
attrib table with:
v.what.rast Contour_points_cats rast=Dartmoor1 col=rast_value
I think that this is an attribute table issue. I have followed the
instructions in Example B
http://grass.itc.it/grass62/manuals/html62_user/v.what.rast.html but
get the following message
v.to.db map=Contour_points option=cat
Reading features...
Updating database...
1 categories read from vector map (layer 1)
1 records selected from table (layer 1)
1 categories read from vector map exist in selection from table
0 records updated/inserted (layer 1)
Record (cat 1) already exists (not inserted)
I have also tried creating and attaching a new table but get the same
result for v.what.vect. Any ideas welcome, thanks for reading!
Rebecca
This mail was received via Mail-SeCure System.
_______________________________________________
grass-user mailing list
[email protected]
http://lists.osgeo.org/mailman/listinfo/grass-user
This mail was received via Mail-SeCure System.
--
Micha Silver
Arava Development Co. +972-52-3665918
http://surfaces.co.il
_______________________________________________
grass-user mailing list
[email protected]
http://lists.osgeo.org/mailman/listinfo/grass-user
