[GRASS-user] raster data to ascii

Glynn Clements glynn at gclements.plus.com
Thu Jun 5 16:26:23 EDT 2008


Hamish wrote:

> > r.resample makes a direct copy of its input, resampled using GRASS'
> > built-in nearest-neighbour resampling, so r.resample only has limited
> > utility.
> > 
> > [AFAICT, it's primary use is to reduce disk space and/or CPU usage. If
> > you will be reading a map repeatedly at a significantly
> > reduced resolution, using a resampled copy may be faster than
> > having GRASS continually resample the higher resolution version.]
> 
> there is a question in the wiki about GRASS 7 development:
>  to remove r.resample (as redundant) or not?
> thoughts?

It may as well stay. Although you can get exactly the same result
using "r.mapcalc newmap = oldmap", r.resample is potentially more
straightforward (it uses G_parser(), with explicit input= and output=
options), and it's useful as an example r.* module.

["r.resamp.interp method=nearest" could theoretically give slightly
different results due to differences in rounding errors. r.resample
has the advantage that it's guaranteed to act as an "identity"
operation.]

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


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