[GRASS-dev] Re: [GRASS GIS] #398: r.watershed with MFD

[GRASS GIS]

#398: r.watershed with MFD
--------------------------+-------------------------------------------------
  Reporter:  mmetz        |       Owner:  grass-dev at lists.osgeo.org
      Type:  enhancement  |      Status:  new                      
  Priority:  minor        |   Milestone:  7.0.0                    
 Component:  Raster       |     Version:  svn-trunk                
Resolution:               |    Keywords:                           
  Platform:  Unspecified  |         Cpu:  Unspecified              
--------------------------+-------------------------------------------------
Comment (by hamish):

 Replying to [ticket:398 mmetz]:
 > With the attached patch I want to submit the last (for the time being)
 modifications to r.watershed. This patch fixes a bug in flag
 initialization, also present in the original (pre-MFD and pre-faster-
 search) version.

 Hi,

 could you isolate that bugfix, i.e. what needs to be backported to 6.4?


 > Flow accumulation with SFD (single flow direction) is unchanged
 > apart from flow accumulation output now being DCELL instead of
 > CELL.

 nice.

 > Flow accumulation with MFD (multiple flow direction) is supported
 > and enabled by default to keep the user interface similar to
 > r.terraflow.

 ok, if there is a major change like that in grass7 it is worth
 noting clearly in the help page. also the help page needs updating
 to reflect that it is no longer "much slower than r.terraflow" and
 the parts referring to the A^T search algorithm, and any references.
 I would guess to leave Ehlschlaeger's paper there for the
 r.watershed ref even if the search algorithm is replaced.


 > Have fun playing around with the convergence factor!

 ...


 Hamish

-- 
Ticket URL: <https://trac.osgeo.org/grass/ticket/398#comment:2>
GRASS GIS <http://grass.osgeo.org>