I would like to know how to use a mask with the v.surf.idw module. I have tried using r.mask with both raster and vector maps, but v.surf.idw always produces a surface encompassing the entire region [0].
Is there any other way of forcing this module to operate within an area of interest?
I would like to know how to use a mask with the v.surf.idw module. I
have tried using r.mask with both raster and vector maps, but v.surf.idw
always produces a surface encompassing the entire region [0].
Is there any other way of forcing this module to operate within an area
of interest?
As explained in [1]: "Raster input maps are automatically masked if a raster map named MASK exists. The MASK is only applied when reading maps from the disk."
This means that the output of v.surf.idw will always cover the entire computational region. If you want to create a map with null values outside the mask, you can use r.mapcalc "masked_map = interpolated_map" while the mask is active.
Is there any way to prevent this module from interpolating new values
for the entire region?
Not AFAIK. You could file an enhancement request. I have no idea how difficult it would be to implement this. v.surf.rst has a 'mask' parameter. I don't know when that comes to play in the algorithm, but it might be an inspiration for v.surf.idw.