[GRASS5] [bug #906] (grass) r.mapcalc: sqrt(-1) - oops

[Markus Neteler]

(cc GRASS5)

On Wed, Jan 23, 2002 at 09:55:52AM +0000, Glynn Clements wrote:
> 
> Markus Neteler wrote:
> 
> > > When talking about r.mapcalc bugs it happened to me few times that r.mapcalc
> > > computed an expression even if one of the maps did not exist without any
> > > complaint.
> > > I did not have time to investigate, but if it really happens it is a pretty
> > > dangerous behavior.
> > 
> > Glynn has fixed the sqrt() problem last night. Please post those case, Helena,
> > if you come across. Of course above error is not acceptable as
> > you just get wrong results.
> > 
> > Glynn, could you revisit r.mapcalc?
> 
> I'll look into it if I'm given a reproducible test case.
> 
> BTW, is there any particular reason for r.mapcalc's use of an
> intermediate reverse-Polish representation?

... about the implementation I do not have much ideas. As
far as I know it is quasi unchanged for years except a few
fixes, the FP extension and cat label copies.
So it might be a candidate for improvement.

Markus