On 11/08/08 12:49, G. Allegri wrote:
It means that I have to select shortest distances from the distance
matrix from outside GRASS (because I can't use MIN, GROUP BY, and
similar statements with db.select with DBF driver), and then update
somehow the points attrbitutes from the previous selection... Mmm,
it's quite a common task, there should be something more
straightforward.
Well, if you move to sqlite (which will be the default in the future),
the task becomes pretty straightforward...
But maybe we can look into adding a minimum threshold to v.distance
(i.e. only record distances above a certain threshold).
Moritz
2008/8/11 Alex Mandel <[EMAIL PROTECTED]>:
G. Allegri wrote:
Hi lis
I need to evaluate the shortest distance between the points of the same
layer .
v.distance fails as to_map and from_map overlap (every shortest
distance is obviously 0: from point to itself). I was considering the
use of network analysis tools... but I don't see a straigthforward way
with them.
Giovanni
How about v.distance -a which creates a distance matrix then you can query
the table for lowest value, group by point and exclude distances of 0.
see http://www.grass.itc.it/gdp/html_grass63/v.distance.html
Alex
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