[GRASS-user] r.mapcalc: compare two maps [RESOLVED]

[Markus Metz]

On Thu, Mar 30, 2017 at 2:46 AM, Rich Shepard <rshepard at appl-ecosys.com>
wrote:
>
> On Wed, 29 Mar 2017, Vaclav Petras wrote:
>
>> As Soeren mentioned in the other part of the thread, use r.univar to get
>> the statistics. Don't rely on just looking at the resulting raster map.
>> There can be things like outliers which may throw the visualization off.
>
>
> Vaclav,
>
>   Here are the results of r.univar on the output of r.mapcalc
"output_diff =
> blocked_h_max - open_h_max":
>
> [...]
> min=-1.89342188835144
> max=0.00093058729544282
> [...]
>
>  [...] I see a small range and many null
> cells, but I expect that because 4 cells on one input DEM are set about
0.6m
> higher elevation than those on the other input DEM.

Apparently something went wrong because min should be 0 and max should be
about 0.6.

The point locations used to edit the original DEM are probably wrong (not
close to the center), and the computational region might have been changed
somewhere in the process of editing the original DEM.

Markus M
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