proj4erl is a NIF-based binding for PROJ.4 library.
It supports three API calls
- init/1 - equivalent of pj_init_plus, returns opaque value which should be used as a reference to initialized projection (equivalent to projPJ type)
- get_def/1 - equivalent of pj_get_def, returns string
- transform/3 - equivalent of pj_transform
Here is an example of usage:
{ok, WGS84} = proj4:init("+init=epsg:4326"),
{ok, CRS2180} = proj4:init("+init=epsg:2180"),
P = {21.049804687501, 52.22900390625},
{ok, P2} = proj4:transform(WGS84, CRS2180, P),
{639951.5695094677, 486751.7840663176} = P2.Initialized projPJ references are being automatically garbage collected.
Feel free to fork and send pull requests!
Clone the project and run (on Ubuntu; adapt apt-get command to install proj4 development files on other systems):
$ sudo apt-get install libproj-dev
$ make- ad-hoc transform calls, with implicit initialization of projPJ and it's caching
- support for linestrings, rings, polygons for speed