[GRASS-dev] [GRASS GIS] #1654: v.extract: allow direct transformation of centroids to polygons

[GRASS GIS]

#1654: v.extract: allow direct transformation of centroids to polygons
-------------------------+--------------------------------------------------
 Reporter:  mlennert     |       Owner:  grass-dev@…              
     Type:  enhancement  |      Status:  new                      
 Priority:  normal       |   Milestone:  7.0.0                    
Component:  Default      |     Version:  unspecified              
 Keywords:               |    Platform:  Unspecified              
      Cpu:  Unspecified  |  
-------------------------+--------------------------------------------------
 A recurrent task is to extract centroids from polygons and to use them as
 points in further analysis. Currently, one has to do this in two steps:

 {{{
 v.extract in=polygonmap out=centroidmap type=centroid
 v.type in=centroidmap out=pointmap type=centroid,point
 }}}

 As this is IMHO such a basic operation, it would be great if v.extract
 could directly create a point layer. This could be implemented in
 different ways (in my order of preference):

 1) If map contains polygons, but no points and type=point is given, then
 extract the centroids as points, if type=centroid extract as centroids.

 2) If type=centroid is given, extract as points by default, but allow to
 extract as centroids by use of a flag

 3) If type=centroid is given, extract as centroids by default, but allow
 to extract as points by use of a flag

 A problem obviously might occur if a map contains a mix of polygons and
 points...

 Moritz

-- 
Ticket URL: <http://trac.osgeo.org/grass/ticket/1654>
GRASS GIS <http://grass.osgeo.org>