[GRASS-dev] [GRASS GIS] #1760: Cannot query vector network nodes

[GRASS GIS]

#1760: Cannot query vector network nodes
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 Reporter:  cmbarton     |       Owner:  grass-dev@…              
     Type:  defect       |      Status:  new                      
 Priority:  major        |   Milestone:  6.4.3                    
Component:  Vector       |     Version:  unspecified              
 Keywords:               |    Platform:  Unspecified              
      Cpu:  Unspecified  |  
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 After trying various things I can now describe more of what is happening.

 Main symptom: you cannot query with a mouse (v.what) nodes on a vector
 network. You can only query the arcs.

 Underlying issues:

 In creating network nodes (v.net nodes) from an existing network map (like
 roads major in the nc_08 demo data), the node points get written to layer
 2 and a set of arcs get written to layer 1. (I'm not sure why it is not
 JUST creating nodes with the v.net node operator. This may be a bug or
 perhaps a "feature"). No attribute info is assigned to nodes created in
 this way, but they must have cats stored in the vector database.

 Trying to query nodes, either 1) query is still not recognizing vectors
 that do not have linked attribute tables (likely a problem here) and/or 2)
 query will not query layer 2.

 So problem 1 is the creation of nodes using v.net on vector
 lines/boundaries. Shouldn't this just be creating nodes in layer 1 rather
 than nodes in layer 2 and arcs in layer 1? v.net connect should then
 connect nodes (i.e., points) with lines/boundaries to create a network.

 Problem 2 is the inability of querying (is this a v.what or a wxgui
 issue?) to return information about points in layer 2 that lack an
 attribute table. Is this a query + layer problem, query + lack of
 attribute table problem or a combination of both?

 The combination of problems 1 and 2 results in the inability to query
 nodes on a network. I'm listing this as a vector problem, but wxgui
 querying may also be involved.

 Michael

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Ticket URL: <http://trac.osgeo.org/grass/ticket/1760>
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