Python package

Installation

The full GeographicLib package can be downloaded from sourceforge. However the python implementation is available as a stand-alone package. To install this, run

pip install geographiclib

Alternatively downloaded the package directly from Python Package Index and install it with

tar xpfz geographiclib-2.0.tar.gz
cd geographiclib-2.0
python setup.py install

It’s a good idea to run the unit tests to verify that the installation worked OK by running

python -m unittest geographiclib.test.test_geodesic

Other links

• Library documentation (all versions): https://geographiclib.sourceforge.io/Python

• GIT repository: https://github.com/geographiclib/geographiclib-python Releases are tagged in git as, e.g., v1.52, v2.0, etc.

• Source distribution: https://sourceforge.net/projects/geographiclib/files/distrib-Python

• GeographicLib: https://geographiclib.sourceforge.io

• The library has been implemented in a few other languages

Change log

• Version 2.0 (released 2022-04-23)

  • Minimum version of Python supported in 3.7. Support for Python 2.x has been dropped.

  • This is a major reorganization with the Python package put into its own git repository, https://github.com/geographiclib/geographiclib-python. Despite this, there are only reasonably minor changes to the package itself.

  • Fix bug where the solution of the inverse geodesic problem with φ₁ = 0 and φ₂ = nan was treated as equatorial.

  • More careful treatment of ±0° and ±180°.

    • These behave consistently with taking the limits

      • ±0 means ±ε as ε → 0+

      • ±180 means ±(180 − ε) as ε → 0+

    • As a consequence, azimuths of +0° and +180° are reckoned to be east-going, as far as tracking the longitude with Geodesic.LONG_UNROLL and the area goes, while azimuths −0° and −180° are reckoned to be west-going.

    • When computing longitude differences, if λ₂ − λ₁ = ±180° (mod 360°), then the sign is picked depending on the sign of the difference.

    • The normal range for returned longitudes and azimuths is [−180°, 180°].

    • A separate test suite test_sign has been added to check this treatment.

• Version 1.52 (released 2021-06-22)

  • Work around inaccurate math.hypot for python 3.[89]

  • Be more aggressive in preventing negative s12 and m12 for short lines.

• Version 1.50 (released 2019-09-24)

  • PolygonArea can now handle arbitrarily complex polygons. In the case of self-intersecting polygons the area is accumulated “algebraically”, e.g., the areas of the 2 loops in a figure-8 polygon will partially cancel.

  • Fixed bug in counting pole encirclings when adding edges to a polygon.

  • Work around problems caused by sin(inf) and fmod(inf) raising exceptions.

  • Math.cbrt, Math.atanh, and Math.asinh now preserve the sign of −0.

• Version 1.49 (released 2017-10-05)

  • Fix code formatting; add tests.

• Version 1.48 (released 2017-04-09)

  • Change default range for longitude and azimuth to (−180°, 180°] (instead of [−180°, 180°)).

• Version 1.47 (released 2017-02-15)

  • Fix the packaging, incorporating the patches in version 1.46.3.

  • Improve accuracy of area calculation (fixing a flaw introduced in version 1.46)

• Version 1.46 (released 2016-02-15)

  • Add Geodesic.DirectLine, Geodesic.ArcDirectLine, Geodesic.InverseLine, GeodesicLine.SetDistance, GeodesicLine.SetArc, GeodesicLine.s13, GeodesicLine.a13.

  • More accurate inverse solution when longitude difference is close to 180°.

  • Remove unnecessary functions, CheckPosition, CheckAzimuth, CheckDistance.