[GRASS-dev] Re: [GRASS GIS] #903: Category color in r.grow

[GRASS GIS]

#903: Category color in r.grow
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  Reporter:  clerici  |       Owner:  grass-dev at lists.osgeo.org
      Type:  defect   |      Status:  new                      
  Priority:  normal   |   Milestone:  6.4.0                    
 Component:  default  |     Version:  6.4.0 RCs                
Resolution:           |    Keywords:                           
  Platform:  Linux    |         Cpu:  Unspecified              
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Comment (by hamish):

 What it does is copy the color table from the input map and applies it to
 the output map.

 When you use the new= option (or old=) with a value which is out of range
 of the old color table, the new value will probably be undefined in the
 old color table.

 With GRASS 6.2 if you run "`r.colors railroads.grown1 color=random`" you
 will see that it did grow, just that the out-of-range color was previously
 coming out as white so you didn't see it.

 With GRASS 6.3.0 and newer instead of undefined colors going to white it
 repeats the color table. If you try with the "roads" raster map and
 new=16, you can see the effect pretty well with d.legend.

 I guess if those options are specified we could explicitly set old= to
 yellow and new= to red (similar to how r.buffer does) to at least set them
 to something.

 Note if the input map's color table has a "default" (*) color defined in
 it this be will be used for undefined values instead of empties being
 filled by the cycling effect.


 Hamish

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Ticket URL: <https://trac.osgeo.org/grass/ticket/903#comment:1>
GRASS GIS <http://grass.osgeo.org>