[GRASS-user] [GRASSLIST:1200] concentric circles/regions in vector

Joel Pitt joel.pitt at gmail.com
Tue Feb 20 18:58:23 EST 2007

Hi all,

I'm trying to create a vector of concentric circles showing a spread
phenomenon and attaching a year to each circle. Currently I am looping
through the following process:

# Create circle
"v.buffer input=%s output=%s buffer=%f" % (centre_map_name,uniform_name,radius)

# add table with year column to uniform_name map
'v.db.addtable map=%s columns="year int" ' % (uniform_name)
# update uniform_name map DB with year
'v.db.update map=%s column=year value=%d' % (uniform_name,year)

# merge with existing map
"v.patch --o -e -a input=%s output=%s" % (uniform_name, merge_map)


This creates a vector map with concentric circles, but I am unable to
select them using "year=2000" - only a point/centroid shows up.

So my question is whether vector types other than centroids/points can
link to a row in a database table?

If not, then can anyone think of a way to do something similar? I'd
rather not have to have excessive numbers of vector maps.

Thanks for any help,


"Unless you try to do something beyond what you have mastered, you
will never grow." -C.R. Lawton

More information about the grass-user mailing list