[GRASS5] Re: proj bugs

[Paul Kelly]

Hello again

On Thu, 3 Jul 2003, H Bowman wrote:

> Testing out the new New Zealand transforms:
>
> g.setproj Segfaults if a datum is already set. If you say "n" to the
> "specify a map datum for this location?" question it works, and you can
> run it again to set a new datum, but if you try and just change the
> transform params it segfaults.
> [see output #1 below]

I can't seem to reproduce this. Can you post a sample of your PROJ_INFO,
PROJ_UNITS and DEFAULT_WIND files that you had prior to running g.setproj?

> =-=
>
> [s|v|r?].proj fails when using the NTv2 distortion grid. Didn't try a
> raster, but I got the same error with both site and vector.
>  (current location nzgd49/NTv2 lat-lon, importing from a WGS84 location)
> [see output #2 below]
> cs2cs with same (cut-and-paste) parameters works correctly.
>
> =-=
>
> Using the 3 and 7 param transform, s.proj runs to completion, but no
> transform is actually done. (happens both ways)
> [see output #3 below]
> cs2cs with same (cut-and-paste) parameters works correctly.

Looks like you found a major bug dating back to the first PROJ
improvements in January. We needed to convert latitude/longitude angles
into radians for PROJ, but this wasn't being done. My new version and Eric
Miler's new version both had this bug so I suppose being consistently
wrong meant nobody picked up on it. The relevant function is pj_do_proj()
in src/libes/proj/do_proj.c and I have fixed it in CVS now.

This bug only showed up when projecting between two lat/long locations.

Thanks for all the testing!

Paul