The Geocode module provides API functions to convert the information you already have into geographic information. It support a variety of input formats and runs them through pluggable backends to produce geographic information. In addition to Latitude / Longitude points, this API also supports more complex geographies such as lines and polygons.

Document these functions following the Doxygen formatting conventions (http://drupal.org/node/1354) providing information on their use, parameters, and return values.