Your are correct - lat/lon distances are not considered in this
module. This can be explained as - lat/lon is NOT finished. This is
just one example of many that doesn't work properly in lat/long.
However, the fix is easy enough, just slower. Use the
G_begin_distance_calculations() and G_distance() routines
(undocumented, still, of course) to calculate distance.
Whew! Thought I was loosing it! As you say its easy to fix...but
you could save me a lot of time...if there is a function that I can
call to tell me whether the xy units are metres or degrees....?
Try try r.surf.sor and see if you like the surfaces better. It handles
only raster based input, but allows the x,y units to be different than
the z units, does (almost) the right thing in lat/long. It is without
manual entry, but "r.surf.sor help" may be enough to get the idea.
I will thanks, I didn't know about it. However, I'm just using the
s.surf.idw routine as a template for s.surf.krig that I am currently
creating.
cheers
chris