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

[Glynn Clements]

Request Tracker wrote:

> this bug's URL: http://intevation.de/rt/webrt?serial_num=2537

> Subject: aitoff/winkel tripel fails on rasters

> When trying to project a raster from geographic (or any other
> projection) to a Winkel Tripel or Aitoff, r.proj spews out VERY many
> 
> pj_transform() failed
> cause: non-convergent inverse meridinal dist
> 
> errors, then gives up with:
> 
> ERROR: Input map is outside current region
> 
> and stops. The region is correct - I use proj (or m.proj2 in
> grass53) to determine the extents needed. And it projects vectors
> (v.proj) just fine.

Neither Aitoff nor Winkel Tripel have defined inverse projections, so
you can't project to those projections with r.proj; you can project
from them, though. v.proj and s.proj use forward projections, so they
don't have this problem (they have the opposite problem: you can
project to such projections, but not from them).

For projections which don't have an inverse, you can use a sequence of
r.to.sites, s.proj and s.surf.rst.

Although, we should make r.proj (or PROJ itself) handle this situation
better.

-- 
Glynn Clements <glynn.clements at virgin.net>