[Proj] bug in PJ_tmerc.c ?

john starjohn at hotmail.com
Thu Jun 2 15:20:54 EDT 2005

Thanks a lot for confirming the problem and the fix! I will try it at work
next week. 

p.s. I doubt if people still use C99 compilers :)

Best Regards

> Date: Wed, 01 Jun 2005 21:26:29 -0400
> From: Gerald Evenden <gerald.evenden at verizon.net>
> Subject: Re: [Proj] bug in PJ_tmerc.c ?
> To: "PROJ.4 and general Projections Discussions"
> <proj at xserve.flids.com>
> Message-ID: <dea42dd2d62aaaaffad81ebebbe215f1 at verizon.net>
> Content-Type: text/plain; charset=US-ASCII; format=flowed
> Ignore my previous correction to the spherical tmerc inverse.
> Current spherical inverse code now contains (from PP1395):
>     double D = xy.y / aks0 + P->phi0, xp = xy.x / aks0;
>     lp.phi = asin(sin(D) / cosh(xp));
>     lp.lam = atan2(sinh(xp), cos(D));
> The above is what will be in the next release of libproj4.  Sign of phi
> carries through automatically.  The problem code must have been a
> messed up carry over from GCTP as I have not touched  the
> spherical stuff in years.  Obviously, no one else has been using it.
> For pre C99 compilers that cannot handle hyperbolic functions:
> it is time to update.  :-)
> Thanks for the error report.  And I apologize for the previous
> erroneous quicky correction.
> _____________________________________
> Jerry and the low riders: Daisy Mae and Joshua.
> "The whole religious complexion of the modern world is due to the
> absence from Jerusalem of a lunatic asylum." Havelock Ellis, 1914

More information about the Proj mailing list