[GRASS-dev] New option in r.neighbors

[Soeren Gebbert]

Hello,
JFYI: i have added a new option "selection" to r.neighbors.

The user can optionally specify a selection map, to compute new values
only where the raster cells of the selection map are not NULL. In case
of NULL cells, the values from the input map are copied into the
output map. This may useful to smooth only parts of an elevation map
(pits, peaks, ...).

Example how to use a selection map with method=average:
input map:
1 1  1 1 1
1 1  1 1 1
1 1 10 1 1
1 1  1 1 1
1 1  1 1 1

selection map, NULL values are marked as *:
* * * * *
* * 1 * *
* 1 1 1 *
* * 1 * *
* * * * *

The output map:
1 1 1 1 1
1 1 2 1 1
1 2 2 2 1
1 1 2 1 1
1 1 1 1 1

Without using the selection map, the output map would look like this:
1 1 1 1 1
1 2 2 2 1
1 2 2 2 1
1 2 2 2 1
1 1 1 1 1


Have fun
Soeren