[Proj] Problem with projections that need support libraries

[Gerald Evenden]

I got involved with resolving a pseudocylindrical projection problem 
where the
projection was mislabeled "Mayr."  This was corrected to a tentative 
name of
"Tobler Parallel Geometric Mean."  This left the true Mayr projection 
unsolve
and a bit difficult as it involves a nonanalytic integral where 
numerical
integration is required.

The kernel is a little nasty but the adaptive integration procedure in 
gsl
(Gnu Scientific Library) handles it nicely.

The problem is this: a libproj4 implementation would most easily be 
performed
by using the gsl routine by linking to the gsl library.  Extracting the 
gsl procedures
would be very, very tedious and error prone.  But by linking to the gsl 
library
transportation is compromised and/or complicated---especially in 
non-unix
environments.

Note: there are other projections which are not implemented due to the 
fact
that complex functions (often available in gsl) are impractical to 
include as
part of libproj4 source.

One option is to put compiler/Makefile switches that would exclude 
projections
that required exotic libraries.  Note: any exotic libraries would be 
required to
be freely available.

Thoughts and comment, please.
_____________________________________
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,