[GRASS-dev] [GRASS GIS] #1874: latitudinal bias in sample points created with r.random

[GRASS GIS]

#1874: latitudinal bias in sample points created with r.random
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 Reporter:  pvanbosgeo  |       Owner:  grass-dev@…              
     Type:  defect      |      Status:  new                      
 Priority:  major       |   Milestone:  7.0.0                    
Component:  Default     |     Version:  svn-trunk                
 Keywords:              |    Platform:  Linux                    
      Cpu:  x86-64      |  
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 Point patterns generated with r.random show a strong latitudinal bias,
 with considerably higher density at higher latitudes.

 The attached screenshot illustrates this. It shows the sum of number of
 points in a moving window (21x21 - created with r.neighbors.

 This is fairly serious because especially at lower sample densities, one
 may not always notice this bias, thus introducing unknowingly such bias in
 analysis.

 Note that points created with v.random do no show a bias. However, this is
 not really an alternative for creating random points within a irregular
 area.

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Ticket URL: <http://trac.osgeo.org/grass/ticket/1874>
GRASS GIS <http://grass.osgeo.org>