[reply outside tracker because not part of original ticket] > > Comment(by hamish): > > Replying to [comment:37 mmetz]: > > Well, then we have to change the way modules are presented in the menus. > > [aside] can we have a README.howto file in the gui/wxpython/xml/ dir? > Every time I edit menudata.xml it seems to get overwritten some time later > by an automated update which I don't see documented anywhere. It sort of > kills my motivation to work on improving the menus anymore. tx. > Weird. Maybe Martin knows more about it. > > > > The mingw32 version of stream_len() does not work 100%, > > could you explain for us humble c++ students? > Premature conclusion from my side. The patch for stream_len() looks ok to me, but something went wrong in filldepr.cc lines 131-132: boundaryStr->seek(0) must be called *after* boundaryStr->stream_len(), otherwise it did not work for me. The reason is unclear to me, maybe a combination of gcc 3.4.5 (mingw-vista special r3) and -O2 (grass default it seems). Or anything else, wild guess is that file stream handling got mixed up.
> > I'd rather you got together with Andrew and/or Laura and co-authored a > journal article racing^W comparing the two with the current offerings from > the other major proprietary GISs. :-) [seriously] > > http://www.cs.duke.edu/geo*/terraflow/speedup.html > In extreme situations, r.terraflow will be faster than r.watershed in disk swap mode, but not that much I bet. In everyday situations, r.watershed in disk swap mode can be faster than r.terraflow mainly because its intermediate files are much smaller and can partially be cached by the system. I am interested in a reasonably fast r.watershed that can handle massive datasets and produces the most realistic results possible. > > Are the core r.watershed algorithms by Ehlschlaeger any more modern? or > have you now replaced and upgraded them to 'state of the art'? (whatever > that means) IMHO, the ingenious part is the A* Search as implemented by Chuck Ehlschlaeger over the whole DEM. My main modification of A* Search was adding a fast priority queue to the search. There are lots of methods out there to remove depressions, but in my experience A* Search produces the most realistic results. There are also lots of flow distribution algorithms out there, but as for sink treatment, there is AFAICT no widely accepted golden solution. I settled for something from 1994 and modified it a bit. > > > > > > r.terraflow and iostream is written for Linux, > > well I knew a version for Arc existed, so thought it possible, > http://wwwmath1.uni-muenster.de:8010/u/jan/TerraFlowExtension/ > Didn't look at the source code. Markus M _______________________________________________ grass-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-dev
