Installing Geospatial libraries

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

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

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
• gdal-bin: for GDAL command line programs like ogr2ogr
• python-gdal for GDAL’s own Python bindings – includes interfaces for raster manipulation

Please also consult platform-specific instructions if you are on Mac OS X 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.

$ sudo make install
$ sudo ldconfig

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 3.4.2 from the GEOS website and untar the source archive:

$ wget http://download.osgeo.org/geos/geos-3.4.2.tar.bz2
$ tar xjf geos-3.4.2.tar.bz2

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

$ cd geos-3.4.2
$ ./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'

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 http://download.osgeo.org/proj/proj-4.9.1.tar.gz
$ wget http://download.osgeo.org/proj/proj-datumgrid-1.5.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-4.9.1.tar.gz
$ cd proj-4.9.1/nad
$ tar xzf ../../proj-datumgrid-1.5.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 http://download.osgeo.org/gdal/1.11.2/gdal-1.11.2.tar.gz
$ tar xzf gdal-1.11.2.tar.gz
$ cd gdal-1.11.2

Configure, make and install:

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

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, the HAS_GDAL flag will be false:

>>> from django.contrib.gis import gdal
>>> gdal.HAS_GDAL
False

The solution is to properly 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