[GRASS-dev] [GRASS GIS] #2122: v.to.db: add eigenvalues of covariance matrix of coordinates

GRASS GIS trac at osgeo.org
Wed Oct 30 07:12:33 PDT 2013


#2122: v.to.db: add eigenvalues of covariance matrix of coordinates
---------------------------------+------------------------------------------
 Reporter:  mlennert             |       Owner:  grass-dev@…              
     Type:  enhancement          |      Status:  new                      
 Priority:  normal               |   Milestone:  7.0.0                    
Component:  Vector               |     Version:  svn-trunk                
 Keywords:  v.to.db eigenvalues  |    Platform:  Unspecified              
      Cpu:  Unspecified          |  
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 [Going on with my series of notes on what would be great to have in
 GRASS:]

 The eigenvalues of the covariance matrix of the coordinates of the
 vertices of a polygon represent the major and minor (+ medium in 3D) axes
 of an ellipse (ellipsoid in 3D) that approximates the polygon. These
 values can be used to approximate different variables in shape analysis
 (length, direction, asymmetry, etc). It would be great if v.to.db could
 calculate these values.

-- 
Ticket URL: <https://trac.osgeo.org/grass/ticket/2122>
GRASS GIS <http://grass.osgeo.org>



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