[GRASS-dev] [GRASS GIS] #1527: vector projection over wrapping boundary is split

GRASS GIS trac at osgeo.org
Fri Dec 30 05:53:09 EST 2011


#1527: vector projection over wrapping boundary is split
----------------------+-----------------------------------------------------
 Reporter:  pertusus  |       Owner:  grass-dev@…              
     Type:  defect    |      Status:  new                      
 Priority:  normal    |   Milestone:  7.0.0                    
Component:  Vector    |     Version:  svn-trunk                
 Keywords:            |    Platform:  Linux                    
      Cpu:  x86-64    |  
----------------------+-----------------------------------------------------
 When I project a vector from a location thet overlaps with a wrapping
 boundary of a map, the vector is split in two.  For example, I have a
 longitude latitude location covering the whole world, that wraps somewhere
 in the Pacific (that is points on the eastern boundary are also on the
 western boundary).  When I project a vector constructed by doing a grid on
 a Lambert equal area location centered somewhere in the Pacific, the grid
 cells (that are, in that case, no more rectangular) that fall on the
 boundary are cut in two, with warnings like:

 {{{
 WARNING: Number of centroids exceeds number of areas: 900 > 847
 WARNING: Number of incorrect boundaries: 507
 WARNING: Number of centroids outside area: 53
 }}}

 I attach a tarball to reproduce the issue (there is a png showing the
 issue in the tarball too).  The script to do everything (setup the lambert
 location, and then the world map and do the png) is ./bug_wrap.sh.

-- 
Ticket URL: <http://trac.osgeo.org/grass/ticket/1527>
GRASS GIS <http://grass.osgeo.org>



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