[GRASS-user] v.overlay: An Observation About Time

[Rich Shepard]

   I have a map of water bodies for the entire state. Yesterday, when I
re-imported it (correctly), it took about 3 hours to complete; most of the
time was waiting for it to 'break boundaries'.

   Today I'm clipping it to a very small region, one drainage basin and parts
of the surrounding basins, yet it's taking about the same amount of time.
Yes, there are a lot of nodes, vertices, and primitives, but I want only
those within the area of the overlaid map. So I'm surprised it's taking as
long as it is.

   This is an extensive original map:

Building topology for vector map <bl_lakes>...
Registering primitives...
220819 primitives registered
4589198 vertices registered
Number of nodes: 158848
Number of primitives: 220819
Number of points: 0
Number of lines: 0
Number of boundaries: 220819
Number of centroids: 0
Number of areas: -
Number of isles: -
Breaking lines...
Removing duplicates...
Cleaning boundaries at nodes...
Breaking lines...

   This is not a complaint, but an observation.

Rich