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))
Sinusoidal projection
Pseudocylindrical equal-area map projection. Also called
Sanson-Flamsteed or Mercartor equal-area projection.
x = (long-long_0)*cos(lat)
y = lat
Miller cylindrical projection
x = long
y = 5/4 * ln(tan(pi/4 + 2/5 * lat))
SEE ALSO
For more general information on map projections:
AUTHOR
Steffen Mueller,
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.