[GRASS-dev] Re: [GRASS GIS] #82: new module: v.to.3d

GRASS GIS trac at osgeo.org
Thu Dec 18 06:25:49 EST 2008


#82: new module: v.to.3d
--------------------------+-------------------------------------------------
  Reporter:  hamish       |       Owner:  martinl         
      Type:  task         |      Status:  assigned        
  Priority:  major        |   Milestone:  6.4.0           
 Component:  Vector       |     Version:  svn-develbranch6
Resolution:               |    Keywords:                  
  Platform:  Unspecified  |         Cpu:  Unspecified     
--------------------------+-------------------------------------------------
Comment (by martinl):

 Replying to [comment:6 martinl]:
 > Replying to [comment:5 hamish]:
 > > Replying to [comment:3 martinl]:
 > > > I am not sure which module to use for reverse transformation
 > > > (3D->2D).
 > >
 > > points, centroids: v.out.ascii | v.in.ascii (without -z or z=). then
 you'd need to copy+merge tables adding in the new z column.
 > >
 > > polyfeatures: v.out.ascii format=standard | awk to strip away the
 third column | v.in.ascii format=standard. I think layer/cat setting at
 end of each feature is ok as it is always like "1 1", never a third
 column.
 > > AFAICT there's no way to keep the data in that 3rd column, as a line
 can only hold a single attribute/cat. the user can summarize with v.univar
 if they want that...?
 >
 > this approach will be very slow for large vector maps... That's reason
 why I would prefer to implement it in GRASS C module.

 Another option would be to rewrite v.to.3d in C.

-- 
Ticket URL: <http://trac.osgeo.org/grass/ticket/82#comment:7>
GRASS GIS <http://grass.osgeo.org>


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