[GRASS5] [bug #2537] (grass) aitoff/winkel tripel fails on rasters

[Markus Neteler]

On Sat, Jul 24, 2004 at 06:37:00PM -0500, William K wrote:
> 
> On Jul 24, 2004, at 2:18 PM, Glynn Clements wrote:
> 
> >
> >William K wrote:
> >
> >>A question about the inverse projection thing - is that a PROJ
> >>limitation, or a general limitation of the Aitoff/Winkel Tripel
> >>projection?
> >
> >I'm not sure how to interpret that question.
> >
> >The proj library includes inverses for some projections, but not all,
> >and not for Aitoff or Winkel Tripel.
> >
> >I suspect that these projections don't have a clearly defined inverse,
> >i.e. the inverse can't be defined in terms of an algebraic expression,
> >and there isn't a "standard" approximation.
> >
> I guess that's what I meant - whether PROJ chose not to include the 
> inverse, or it's just not definable or available.  I'm thinking not 
> included - though I haven't tried, the Arc docs don't say it isn't 
> possible.  Maybe it's just difficult and ESRI spent the time (they 
> certainly have the resources) to figure it out.
> 
> Oh well.

William,

it might be a good idea to contact the PROJ4 people (the authors
of that library):

 http://www.remotesensing.org/proj/
 -> Mailing List

Maybe, if there is interest and the definitions available,
they'll implement it?

Markus