On 09/23/2010 07:36 PM, Bryan Keith wrote:
What OS are you on? what version of GRASS, and what GUI?
I'll answer these questions anyway, but I figured out the v.digit problem
(see below).
Windows XP
GRASS 6.4.0
wxGUI
So you'll be using the tcltk digitizer. (wxGui doesn't work yet in Windows)
OK, getting closer, I think. The reason v.digit wasn't working was
because g.region was set incorrectly. Now I can look at the various maps
with v.digit and see the different colors of the lines and nodes. In the
meantime I created a very simple example and processed that map and was
able to get results that I expected. So then I looked at the one that
worked and the one that didn't using v.digit to see what the differences
were.
The files that doesn't have all the areas that I expect has lines that are
displayed orange (Boundary (1 area)) while the correct version has lines
that are display green (Boundary (2 areas)). Could that be why I'm not
getting all the areas that I expect? All the nodes look correct (no red
ones). How do I fix this? An option in v.clean?
Orange boundaries are duplicates - overlapping lines - that GRASS
topology doesn't allow.
You should be able to get rid of these with:
"v.clean in=... out=... tool=break,bpol,rmdupl"
But I've never had good luck with this.
The alternative that might work better for you:
Re-import the layer from the original shapefiles (or where ever they
came from) but use the "type=line" option to v.in.ogr. (No centroids
will be created)
Now do v.clean on this new GRASS vector, using tool=snap,break,rmdupl.
Next use
"v.type ... type=line,boundary"
to convert the (cleaned) lines to boundaries, and then
"v.centroids ... opt=add"
to create area centroids inside each closed boundary.
--
Micha
Bryan
--
Micha Silver
Arava Development Co. +972-52-3665918
http://surfaces.co.il
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