distance calculations in s.surf.idw

Chris Skelly chris at mqatmos.cic.mq.edu.au
Wed Feb 12 11:52:15 EST 1992

>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


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