NAME
    Astro::MapProjection - A few simple map projections (Hammer, sinusoidal,
    ...)

SYNOPSIS
      use Astro::MapProjection qw/miller_projection hammer_projection sinusoidal_projection/;
      my ($x, $y) = hammer_projection($latitude, $longitude);

DESCRIPTION
    Simple XS module that implements a few map projections (see below). Let
    me know if you need any others.

  EXPORT
    None by default. You can choose to import the following functions:

      miller_projection
      hammer_projection
      sinusoidal_projection

PROJECTIONS
  Hammer projection
    An equal area map projection after Ernst Hammer.

      x = 2*sqrt(2) * cos(lat)*sin(long/2) /
          sqrt(1+cos(lat)*cos(long/2))
      y = sqrt(2)*sin(lat) / 
          sqrt(1+cos(lat)*cos(long/2))

    <http://en.wikipedia.org/wiki/Hammer_projection>

  Sinusoidal projection
    Pseudocylindrical equal-area map projection. Also called
    Sanson-Flamsteed or Mercartor equal-area projection.

      x = (long-long_0)*cos(lat)
      y = lat

    <http://en.wikipedia.org/wiki/Sinusoidal_projection>

  Miller cylindrical projection
      x = long
      y = 5/4 * ln(tan(pi/4 + 2/5 * lat))

    <http://en.wikipedia.org/wiki/Miller_cylindrical_projection>

SEE ALSO
    For more general information on map projections:
    <http://en.wikipedia.org/wiki/Map_projection>

AUTHOR
    Steffen Mueller, <smueller@cpan.org>

COPYRIGHT AND LICENSE
    Copyright (C) 2009 by Steffen Mueller

    This library is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself, either Perl version 5.8.0 or, at
    your option, any later version of Perl 5 you may have available.