[Proj] Receiving "pj_transform(): Unknown error" while trying to use cs2cs from rpoly to utm

[John Buonagurio]

Hi,

PROJ.4 only supports the forward transformation (from lon/lat to projected). The inverse transformation isn't implemented unfortunately for rectangular polyconic:

<https://github.com/OSGeo/proj.4/blob/master/src/PJ_rpoly.c#L12>

("no inv.")

Has anyone looked into this? The inverse is described in Yang/Snyder/Tobler.

John


From: proj-bounces at lists.maptools.org [mailto:proj-bounces at lists.maptools.org] On Behalf Of Resnick, Jessica
Sent: Tuesday, September 27, 2016 2:06 PM
To: proj at lists.maptools.org
Subject: [Proj] Receiving "pj_transform(): Unknown error" while trying to use cs2cs from rpoly to utm

Hi All,

I am trying to convert some points from rpoly to utm. I have tried typing Cartesian coordinates and cartographic coordinates and both result in the error: 
<cs2cs>: while processing file: <stdin>, line 1
pj_transformation(): Unknown error

For some reason it works correctly if I go from utm to rpoly, but that is not what I am trying to do.
Here is my code:
cs2cs +proj=rpoly +lat_ts=25.066667 +lon_0=-80.636667 +ellps=bessel +to +proj=utm +zone 17 +ellps=WGS84
I tried inputting: 
-80.4666667 +24.983333333
and got:   *                  *       0.00
17151.59  2799896.42
and got:    *                 *       0.00

Can anyone tell me what I am doing wrong?

Thanks!