# Overview

## Visual Units Tools

This is/will be a collection of tools developed at Visual Units (www.visualunits.se) and released as open source under the MIT license.

### distance

A Python implementaion (optionally using a C library for speed) for computing distances on the globe using the WGS84 ellipsoid. It is a direct translation of Chris Veness' implementation of Vincenty inverse formula (in Javascript) which you can find at http://www.movable-type.co.uk/scripts/latlong-vincenty.html.

Usage:

>> import distance
>> distance.distance(lat1, lon1, lat2, lon2)
returns distance in meters as a floating point number


If distance.c is compiled into cDistance.so and can be found for loading, it will be used instead of the Python implementation. To compile the c file, you can, for example, use:

gcc -fPIC -shared -o cDistance.so distance.c


Copyright (C) 2008-2013 Visual Units AB

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.