Adjacency matrix in GRASS

Question

I have a line shapefile that I use as network. I connect a set of point to it using "v.net operation connect" command. .

My questions are:

(i) how can I get the list of neighbors for each "connected" point (or the adjacency matrix between all the points)? I mean a list like A-B, A-D, B-A, B-C, C-D, C-B, ...

(ii) how can I simplify the network by dissolving/merging unnecessary edges between my points? I mean merging edges 1-2, 3-4, 5-6 and so on.

It seems quite simple but I am not able to manage it...

Answer 1

As for the second part of your question, v.build.polylines will connect line "segments", removing nodes as long as exactly two line segments are connected. All intersections with 3 or more segments will be left as nodes.

I Can't help with the list of nearest neighbors.

Answer 2

i) seems like nearest point analysis; it is available in ArcGIS, and in GME (search Hawths Tools (Spatial Ecology)), ii) a line clean should sort this out