[GRASSLIST:5962] Re: v.surf.idw (point in region!!!)

[Paul Kelly]

On Wed, 2 Mar 2005, Massimiliano Cannata wrote:

> Hi,
> I see that in this new improved version (grass 6beta2) the interpolation 
> consider only the vector points that falls into the current region, if i 
> remember corrctly in the older version it was possible set a flag to choose 
> if consider all points or just the sites in region.

The disable indexing -n flag is still there. And performs this purpose if 
you haven't got too many points. You will lose the feature though that if 
more than one point falls into a raster cell they are averaged; with the 
-n flag it will just be the point closest to the centre of the cell that 
is used for the interpolated value. But if your points are far apart this 
is unlikely to be a problem.

I have updated the descriptions to be a bit clearer.

The alternative way is of course as the man page says---enlarge the region 
to encompass all the points and use a mask to define where you want the 
interpolation to be done.

Paul