Dear Grass Users,
A correction to the earlier email (syntax error on v.patch)
Is there a method of patching together multiple vector files into one and still
retain the attributes found within each file? (My intent is to have one vector
file with all the state boundaries, and if I run d.what.vect on that file, I
point, click, and get the state name for each point and click.)Here is what has been tried already...
With multiple vector files, one file per state boundary,I run v.patch with a
command like the following :v.patch input=or.bnd,ca.bnd,wa.bnd,id.bnd output=west.bnd
Then v.support with :
v.support map=west.bnd
What I get are all the lines but the area becomes the perimeter of all the
states specified in the v.patch command. v.digit shows the lines bordering the
states become open area lines. Am I resolved to manually correcting the file
with v.digit?Wayne Gibson
Oregon State University
If I understand correctly, you have patched 4 western states together.
If each of the input files are complete, then your output file will
have duplicate edges for each mutual boundary. For instance the
Washington/Oregon boundary will have a line contributed from WA and
one from Oregon. If these have been digitized individually, the
two lines won't be identical. If they are identical, I suggest you
try v.spag -i, this does an identical line removal. Depending on
the common borders you may still have to go into v.digit to clean.
If you lose the attributes in the process, you can "cheat" by
using cat to append the original dig_att files together to create
the new one. You can do a similar thing with the input dig_cats
files, but you'll need to be careful about the header lines.
Sue Huse
REGIS
UC Berkeley