[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:  query, vector  |    Platform:  Unspecified              
      Cpu:  Unspecified    |  
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Comment(by mmetz):

 Replying to [comment:1 cmbarton]:
 > Here is additional information.
 >
 > v.net does not create an attribute table for nodes, even if they are
 created from a set of points that DO have an attribute table.

 Attached to which layer in the original input vector?

 I have long thought about updating the v.net module with regard to layer
 management, but did not yet get to do it: for v.net, it should be possible
 to specify the input arc and node layer, default to 1 for each. Output arc
 layer is 1, output node layer is 2 (current behaviour and required by the
 default settings of most of the v.net.* modules). Any attribute tables
 attached would be copied, and the vector feature attributes changed
 accordingly.

 >
 > creates a network of streets and firestations. The attributes from the
 streets_wake file get copied over into the arcs of the new
 forestation_network vector network file. But the attributes from the
 firestations do not. This is the cause of the inability to query the
 nodes. If I manually run v.db.connect to connect the nodes of
 forestation_network to the forestations attribute table (connected to
 nodes in layer 2), then I CAN query the nodes.

 This is a problem of the wxGUI. v.what from the command line works just
 fine, same in the tcl/tk GUI. The wxGUI, in all versions, queries the
 attribute tables rather than the vector features. This is not conforming
 to GRASS vector design.
 >
 > So the main problem is in how v.net creates networks not how v.what (and
 wxgui) queries the network. In fact, there is no problem querying nodes in
 layer 2 once they have an attribute table.
 >
 > BUT, querying nodes still should at least show the cat values, even if
 there is no attribute table. So there is still a query issue here.

 Please file a bug for the wxGUI in this regard.

 Markus M

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Ticket URL: <http://trac.osgeo.org/grass/ticket/1760#comment:3>
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