# Django 2.1.8.dev20190330215650 documentation

# Installing Geospatial libraries

GeoDjango uses and/or provides interfaces for the following open source geospatial libraries:

Program | Description | Required | Supported Versions
--- | --- | --- | ---
GEOS | Geometry Engine Open Source | Yes | 3.6, 3.5, 3.4
PROJ.4 | Cartographic Projections library | Yes (PostgreSQL and SQLite only) | 4.9, 4.8, 4.7, 4.6, 4.5, 4.4
GDAL | Geospatial Data Abstraction Library | Yes | 2.2, 2.1, 2.0, 1.11, 1.10, 1.9
GeoIP | IP-based geolocation library | No | 2
PostGIS | Spatial extensions for PostgreSQL | Yes (PostgreSQL only) | 2.5, 2.4, 2.3, 2.2, 2.1
SpatiaLite | Spatial extensions for SQLite | Yes (SQLite only) | 4.3, 4.2, 4.1

Note that older or more recent versions of these libraries may also work totally fine with GeoDjango. Your mileage may vary.

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The GeoDjango interfaces to GEOS, GDAL, and GeoIP may be used independently of Django. In other words, no database or settings file required -- just import them as normal from `django.contrib.gis`.

On Debian/Ubuntu, you are advised to install the following packages which will install, directly or by dependency, the required geospatial libraries:

    $ sudo apt-get install binutils libproj-dev gdal-bin

Optional packages to consider:

- `libgeoip1`: for GeoIP support
- `python-gdal` for GDAL's own Python bindings -- includes interfaces for raster manipulation

Please also consult platform-specific instructions if you are on macOS or Windows.

## Building from source

When installing from source on UNIX and GNU/Linux systems, please follow the installation instructions carefully, and install the libraries in the given order. If using MySQL or Oracle as the spatial database, only GEOS is required.

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On Linux platforms, it may be necessary to run the `ldconfig` command after installing each library. For example:

    $ sudo make install
    $ sudo ldconfig

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macOS users must install Xcode in order to compile software from source.

### GEOS

GEOS is a C++ library for performing geometric operations, and is the default internal geometry representation used by GeoDjango (it's behind the "lazy" geometries). Specifically, the C API library is called (e.g., `libgeos_c.so`) directly from Python using ctypes.

First, download GEOS from the GEOS website and untar the source archive:

    $ wget https://download.osgeo.org/geos/geos-X.Y.Z.tar.bz2
    $ tar xjf geos-X.Y.Z.tar.bz2

Next, change into the directory where GEOS was unpacked, run the configure script, compile, and install:

    $ cd geos-X.Y.Z
    $ ./configure
    $ make
    $ sudo make install
    $ cd ..

#### Troubleshooting

##### Can't find GEOS library

When GeoDjango can't find GEOS, this error is raised:

    ImportError: Could not find the GEOS library (tried "geos_c"). Try setting GEOS_LIBRARY_PATH in your settings.

The most common solution is to properly configure your Library environment settings or set GEOS_LIBRARY_PATH in your settings.

If using a binary package of GEOS (e.g., on Ubuntu), you may need to Install binutils.

##### `GEOS_LIBRARY_PATH`

If your GEOS library is in a non-standard location, or you don't want to modify the system's library path then the `GEOS_LIBRARY_PATH` setting may be added to your Django settings file with the full path to the GEOS C library. For example:

    GEOS_LIBRARY_PATH = '/home/bob/local/lib/libgeos_c.so'

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The setting must be the full path to the C shared library; in other words you want to use `libgeos_c.so`, not `libgeos.so`.

See also My logs are filled with GEOS-related errors.

### PROJ.4

PROJ.4 is a library for converting geospatial data to different coordinate reference systems.

First, download the PROJ.4 source code and datum shifting files [1]:

    $ wget https://download.osgeo.org/proj/proj-X.Y.Z.tar.gz
    $ wget https://download.osgeo.org/proj/proj-datumgrid-X.Y.tar.gz

Next, untar the source code archive, and extract the datum shifting files in the `nad` subdirectory. This must be done prior to configuration:

    $ tar xzf proj-X.Y.Z.tar.gz
    $ cd proj-X.Y.Z/nad
    $ tar xzf ../../proj-datumgrid-X.Y.tar.gz
    $ cd ..

Finally, configure, make and install PROJ.4:

    $ ./configure
    $ make
    $ sudo make install
    $ cd ..

### GDAL

GDAL is an excellent open source geospatial library that has support for reading most vector and raster spatial data formats. Currently, GeoDjango only supports GDAL's vector data capabilities [2]. GEOS and PROJ.4 should be installed prior to building GDAL.

First download the latest GDAL release version and untar the archive:

    $ wget https://download.osgeo.org/gdal/X.Y.Z/gdal-X.Y.Z.tar.gz
    $ tar xzf gdal-X.Y.Z.tar.gz
    $ cd gdal-X.Y.Z

Configure, make and install:

    $ ./configure
    $ make # Go get some coffee, this takes a while.
    $ sudo make install
    $ cd ..

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Because GeoDjango has its own Python interface, the preceding instructions do not build GDAL's own Python bindings. The bindings may be built by adding the `--with-python` flag when running `configure`. See GDAL/OGR In Python for more information on GDAL's bindings.

If you have any problems, please see the troubleshooting section below for suggestions and solutions.

#### Troubleshooting

##### Can't find GDAL library

When GeoDjango can't find the GDAL library, configure your Library environment settings or set GDAL_LIBRARY_PATH in your settings.

##### `GDAL_LIBRARY_PATH`

If your GDAL library is in a non-standard location, or you don't want to modify the system's library path then the `GDAL_LIBRARY_PATH` setting may be added to your Django settings file with the full path to the GDAL library. For example:

    GDAL_LIBRARY_PATH = '/home/sue/local/lib/libgdal.so'

Footnotes

[1] | The datum shifting files are needed for converting data to and from certain projections. For example, the PROJ.4 string for the Google projection (900913 or 3857) requires the `null` grid file only included in the extra datum shifting files. It is easier to install the shifting files now, then to have debug a problem caused by their absence later.

[2] | Specifically, GeoDjango provides support for the OGR library, a component of GDAL.