[GRASS-dev] Re: [GRASS GIS] #577: v.in.ogr: imported GPX file results in N=0, W=0

[GRASS GIS]

#577: v.in.ogr: imported GPX file results in N=0, W=0
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  Reporter:  hamish  |       Owner:  grass-dev at lists.osgeo.org
      Type:  defect  |      Status:  new                      
  Priority:  normal  |   Milestone:  6.4.0                    
 Component:  Vector  |     Version:  svn-develbranch6         
Resolution:          |    Keywords:  v.in.ogr, gpx            
  Platform:  Linux   |         Cpu:  x86-32                   
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Comment (by hamish):

 Replying to [comment:3 mmetz]:
 > Grass vector extends are calculated when topology is built,
 > based on the primitives, which happens after all layers were
 > imported by v.in.ogr, IOW grass vector extends should be
 > calculated independent of the OGR layer extends. If all features
 > are somewhere around 170, -46 and nowhere near 0,0, v.info
 > should report extends accordingly. That's why I think there may
 > be a bug in the vector libraries when building topology because
 > v.out.ascii confirmed that no points where anywhere near 0,0.
 >
 > Hamish, can you do a bit more testing? Are the extends still wrong
 >   * after rebuilding topology with v.build?

 yes

 hmmm.... nodes 1 & 2:

 {{{
 G65> v.build gps_trk_gpx_import option=dump
 ---------- TOPOLOGY DUMP ----------
 N,S,E,W,T,B: 0.000000, -46.055889, 170.724047, 0.000000, 0.000000,
 0.000000
 Nodes (3838 nodes, alive + dead ):
 node = 1, n_lines = 1, xy = 0.000000, 0.000000
   line =   1, type = 2, angle = -9.000000
 node = 2, n_lines = 1, xy = 0.000000, 0.000000
   line =  -1, type = 2, angle = -9.000000
 node = 3, n_lines = 4, xy = 170.641103, -45.827688
   line =   7, type = 1, angle = -9.000000
   line = 707, type = 1, angle = -9.000000
   line =   2, type = 2, angle = 2.753561
   line =   3, type = 2, angle = 2.753561
 node = 4, n_lines = 2, xy = 170.189732, -46.050674
   line = 706, type = 1, angle = -9.000000
   line =  -2, type = 2, angle = 0.575716
 ...
 }}}


 >   * when importing track_points only from the GPX file?



 >   * when importing all shapefiles at once into one grass vector?
 >   * when importing the shapefile track_points only?
 >
 > v.in.ogr could also be modified to skip empty OGR layers (Feature Count:
 0). I don't know if there are OGR-recognized vector formats where there
 can be some info in a layer with no features, then empty layers should not
 be skipped.
 >
 > Markus M

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Ticket URL: <https://trac.osgeo.org/grass/ticket/577#comment:4>
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