[GRASS-dev] [GRASS GIS] #399: Added "backlink" functionality to r.walk, r.cost & r.drain

[GRASS GIS]

#399: Added "backlink" functionality to r.walk, r.cost & r.drain
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 Reporter:  cnielsen  |       Owner:  grass-dev at lists.osgeo.org
     Type:  defect    |      Status:  new                      
 Priority:  major     |   Milestone:  6.4.0                    
Component:  Raster    |     Version:  unspecified              
 Keywords:            |    Platform:  All                      
      Cpu:  All       |  
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 I have updated the r.walk, r.cost and r.drain modules to include
 "back-link raster" functionality. Currently the path created by
 r.drain does not necessarily take THE path through a cost surface,
 that the cost accumulation algorithm took to generate that cost
 surface. My updates add an "outdir" raster as an output from the
 r.drain and r.cost modules which creates a backlink raster, or a
 raster surface of the movements made to create the cost surface
 (recorded in degrees). I then modified r.drain to read this surface
 when it's given the "-d" flag.

 I have tested it on my win32/vista build (mingw/msys), but not on linux or
 mac builds. Since this is my first patch, I have added extensive
 commenting which can probably be removed later.

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Ticket URL: <http://trac.osgeo.org/grass/ticket/399>
GRASS GIS <http://grass.osgeo.org>