[GRASS-dev] [GRASS GIS] #2298: r.stream.order hack= generates order 1 single pixels

[GRASS GIS]

#2298: r.stream.order hack= generates order 1 single pixels
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 Reporter:  hcho            |       Owner:  grass-dev@…              
     Type:  defect          |      Status:  new                      
 Priority:  major           |   Milestone:  7.1.0                    
Component:  Raster          |     Version:  svn-trunk                
 Keywords:  r.stream.order  |    Platform:  Linux                    
      Cpu:  x86-64          |  
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 Running r.stream.order hack= assigns to single pixel tributaries order 1
 instead of 2. I believe that any tributaries should get assigned order >=
 2 and the main stream gets 1.

 I'm attaching screenshots of a streams and output hack raster maps. In the
 streams map, the blue and green streams merge and flow into the gray one.
 The gray stream has a small one pixel tributary coming in (center lowest
 pixel) and this pixel becomes an order 1 (yellow) in the hack output. I
 think this pixel should become 2 (green) because it's a tributary to the
 gray main stream. I have a lot these single pixel dangling tributaries and
 simply selecting order 1 doesn't make a nice looking single polyline
 representing the main stream.

 Or maybe, I'm misunderstanding something in the Hack's order algorithm?

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Ticket URL: <https://trac.osgeo.org/grass/ticket/2298>
GRASS GIS <http://grass.osgeo.org>