/ 
GIS-Distance-0.10
River stage two • 6 direct dependents • 21 total dependents
/ GIS::Distance

NAME

GIS::Distance - Calculate geographic distances.

SYNOPSIS

use GIS::Distance;

# Use the GIS::Distance::Haversine formula by default:
my $gis = GIS::Distance->new();

# Or choose a different formula:
my $gis = GIS::Distance->new( 'Polar' );

my $distance = $gis->distance( $lat1,$lon1 => $lat2,$lon2 );

print $distance->meters();

DESCRIPTION

This module calculates distances between geographic points on, at the moment, plant Earth. Various formulas are available that provide different levels of accuracy versus calculation speed tradeoffs.

METHODS

distance

my $distance = $gis->distance( $lat1,$lon1 => $lat2,$lon2 );

Returns a Class::Measure::Length object for the distance between the two degree lats/lons.

See "distance_km" to return raw kilometers instead.

distance_km

This works just like "distance" but return a raw kilometer measurement.

ATTRIBUTES

formula

Returns the formula name which was passed as the first argument to new().

The formula can be specified as a partial or full module name for that formula. For example, if the formula is set to Haversine as in:

my $gis = GIS::Distance->new( 'Haversine' );

Then the following modules will be looked for in order:

GIS::Distance::Fast::Haversine
GIS::Distance::Haversine
Haversine

Note that a Fast:: version of the class will be looked for first. By default the Fast:: versions of the formulas, written in C, are not available and the pure perl ones will be used instead. If you would like the Fast:: formulas then install GIS::Distance::Fast and they will be automatically used.

args

Returns the formula arguments, an array ref, containing the rest of the arguments passed to new(). Most formulas do not take arguments. If they do it will be described in their respective documentation.

module

Returns the fully qualified module name that "formula" resolved to.

SEE ALSO

GIS::Distance::Fast - C implmentation of some of the formulas shipped with GIS::Distance. This greatly increases the speed at which distance calculations can be made.

FORMULAS

GIS::Distance::Cosine

GIS::Distance::GeoEllipsoid

GIS::Distance::GreatCircle

GIS::Distance::Haversine

GIS::Distance::MathTrig

GIS::Distance::Polar

GIS::Distance::Vincenty

TODO

  • Create a GIS::Coord class that represents a geographic coordinate. Then modify this module to accept input as either lat/lon pairs, or as GIS::Coord objects.

  • Create some sort of equivalent to Geo::Distance's closest() method.

  • Write a formula module called GIS::Distance::Geoid. Some very useful info is at http://en.wikipedia.org/wiki/Geoid.

BUGS

See "BROKEN" in GIS::Distance::Polar.

SUPPORT

Please submit bugs and feature requests to the GIS-Distance GitHub issue tracker:

https://github.com/bluefeet/GIS-Distance/issues

AUTHORS

Aran Clary Deltac <bluefeet@cpan.org>

LICENSE

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.