[GRASS-dev] FW: list GRASSLIST: List Message Rejected
michael.barton at asu.edu
Fri Feb 23 03:28:18 CET 2007
I replied to this only to have it bounced because it came from the old
Baylor list. Can we turn that off?
Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University
> Nesting a lot of vector circles inside each other, then selecting them for
> display could get rather tricky (though I'm sure it's doable). However, you
> might be able to do this better with raster buffers.
> Here is a simple example, using 2 sites (cat 12 and 15) from the Spearfish
> dataset. First I transformed the 2 site points to raster. Then I ran
> r.buffer to create a series of concentric rings around the sites of
> different radii, to simulate a spread event of variable yearly intensity.
> r.buffer input=archsites_12_15 output=buffer_12_15
> distances=500,800,1300,1500,2000,2300 units=meters
> Then, I can simply display any buffer ring by specifying its cat (in this
> case equal to the year in the sequence 1-7, rather than calendar years) in
> the d.rast command (I use the "values to display" entry in the GUI raster
> options panel).
> d.rast map=buffer_12_15
> ...will display all the buffer rings
> d.rast map=buffer_12_15 catlist=1-3
> ...will display the starting point and next innermost 2 buffer rings
> d.rast map=buffer_12_15 catlist=5-7
> ...will display the outermost 3 buffer rings
> d.rast map=buffer_12_15 catlist=2,5,7
> ...will display buffer rings 2, 5, and 7
> This could easily be animated in a script, all with with just a single
> raster buffer map.
> On 2/20/07 4:58 PM, "Joel Pitt" <joel.pitt at gmail.com> wrote:
>> 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" %
>> # 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,
> Michael Barton, Professor of Anthropology
> School of Human Evolution & Social Change
> Center for Social Dynamics & Complexity
> Arizona State University
> phone: 480-965-6213
> fax: 480-965-7671
> www: http://www.public.asu.edu/~cmbarton
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