[GRASS-dev] Raster format and dual function module

[Glynn Clements]

Hamish wrote:

> > > could you write some precise/focused command line examples of
> > > "common" or likely intensive operations? (using spearfish)
> > 
> > No. I'm a programmer, not a geoscientist; that's why I'm asking
> > someone else to do it. Anything I came up with would be a contrived
> > example rather than "common usage". It would probably be more useful
> > if people could try it on "real" examples.
> > 
> > Having said that, the most interesting cases are ones where the
> > processing is relatively simple (so that the performance of libgis'
> > I/O routines is the dominant factor) and which tend to be slow (making
> > a 20-second operation take 10 seconds is more useful than making a
> > 2-second operation take 1 second).
> 
> so a good candidate for a high libgis IO module + slow task might be,
> 
> (spearfish60)
> g.region elevation.10m
> r.patch out=merge in=roads,railroads,streams,tractids,transport.misc,rstrct.areas,trn.sites,landuse,fields,erode.index
> 
> or the r.mapcalc equivalent of the same task?

Probably. Or simple r.mapcalc commands. Actually, for test I/O,
r.resample is probably as good a choice as any.

I suppose that the issue has as much to do with the type of maps
people are actually using (map resolution, region resolution,
CELL/FCELL/DCELL input/output formats, distribution of values,
proportion of nulls etc) as with the processes performed upon them.

-- 
Glynn Clements <glynn at gclements.plus.com>