[GRASS5] [bug #859] (grass) raster data at lower resolution: no resampling...

Helena Mitasova hmitaso at unity.ncsu.edu
Tue Nov 27 10:31:04 EST 2001

Markus Neteler wrote:

> O.k. - the problem is that I have no idea what "resampled" means in
> this case. It seems that we have to study the related sources.I just want
> to understand what's happening.

I guess you should really look at the source and then write what you have found
into the prog manual and users manual (probably for g.region entry).
Does anybody know what it is doing already, to save Markus some time?

> Does it make sense print a warning in this case? To make the user
> aware that the resolution doesn't match?
> At least when exporting data or using r.mapcalc this is quite important.

I agree with that, but I am not sure how much work it would be.
It would certainly be beneficial if r.mapcalc let user know
e.g. when computing C=A+B+D it could write : Warning, resampling map A to match
the resolution.
When exporting, it would be useful too. In r.flow, where it really matters,
we just say that "your resolution does not match the current resolution" and exit
so the user has to fisrt change his region to that of the elevation input or
his elevation. So it is really application and data dependent.


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