
=========
PyGeodesy
=========

A pure Python implementation of ``geodesy`` tools for various ellipsoidal
and spherical earth models using precision trigonometric, vector-based,
exact, elliptic, iterative and approximate methods for geodetic
(lat-/longitude), geocentric (ECEF_ cartesian) and certain `triaxial
ellipsoidal`_ coordinates.

Transcoded from `JavaScript originals`_ by *Chris Veness (C) 2005-2022*
and from several `C++ classes`_ by *Charles F.F. Karney (C) 2008-2023*
and published under the same `MIT License`_.

There are four modules for ellipsoidal earth models, *ellipsoidalExact*,
*-Karney*, *-Vincenty* and *-Nvector* and two for spherical ones,
*sphericalTrigonometry* and *-Nvector*.  Each module provides a geodetic
LatLon_ and a geocentric Cartesian_ class with methods and functions to
compute distance, surface area, perimeter, initial and final bearing,
intermediate and nearest points, circle intersections and secants, path
intersections, `3-point resections`_, rhumb and rhumb lines, trilateration
(by intersection, by overlap and in 3d), conversions and unrolling, among
other things.  For more information and further details see the documentation_,
the descriptions of `Latitude/Longitude`_, Vincenty_ and `Vector-based`_
geodesy, the original `JavaScript source`_ or docs_ and *Karney*\'s Python
geographiclib_ and `C++ GeographicLib`_.

Also included are modules for conversions to and from `Cassini-Soldner`_,
ECEF_ (Earth-Centered, Earth-Fixed cartesian), UTM_ (Universal Transverse
Mercator and Exact_), UPS_ (Universal Polar Stereographic) and `Web
Mercator`_ (Pseudo-Mercator) coordinates, MGRS_ (Military Grid Reference
System, UTM *and* UPS) and OSGR_ (British Ordinance Survery Grid Reference)
grid references, TRF_ (Terrestrial Reference Frames) and modules to encode
and decode EPSG_, Geohashes_, `Georefs (WGRS)`_ and `Garefs (GARS)`_.

Other modules provide `Albers equal-area`_ projections, equidistant_ and
other *azimuthal* projections, Lambert *conformal conic* projections and
positions, functions to clip paths or polygons of *LatLon* points using
the `Cohen-Sutherland`_, `Forster-Hormann-Popa`_, `Greiner-Hormann`_,
`Liang-Barsky`_ and `Sutherland-Hodgman`_ methods or to perform *boolean*
operations between (composite) polygons, functions to simplify_ or linearize
a path of *LatLon* points (or a `numpy array`_), including implementations
of the `Ramer-Douglas-Peucker`_, `Visvalingam-Whyatt`_ and `Reumann-Witkam`_
algorithms and modified versions of the former.  Other classes interpolate_
the Height_ of *LatLon* points and Geoid_ models or compute various Fréchet_
or Hausdorff_ distances.

Installation
============

To install PyGeodesy, type ``python[3] -m pip install PyGeodesy`` or
``python[3] -m easy_install PyGeodesy`` in a terminal or command window.

If the wheel ``PyGeodesy-yy.m.d-py2.py3-none-any.whl`` is missing in `PyPI
Download files`_, download the file from `GitHub/dist`_.  Install that with
``python[3] -m pip install <path-to-downloaded-wheel>`` and verify with
``python[3] -m pygeodesy``.

Alternatively, download ``PyGeodesy-yy.m.d.zip`` from PyPI_ or GitHub_,
``unzip`` the downloaded file, ``cd`` to directory ``PyGeodesy-yy.m.d``
and type ``python[3] setup.py install``.

To run all PyGeodesy tests, type ``python[3] test/run.py`` or type
``python[3] test/unitTestSuite.py`` before or after installation.

Dependencies
============

Installation of *Karney*\'s Python package geographiclib_ is optional,
but required to use modules ``ellipsoidalKarney`` and ``css``, ``azimuthal``
classes ``EquidistantKarney`` and ``GnomonicKarney`` and the
``HeightIDWkarney`` interpolator.

Both numpy_ and scipy_ must be installed for most Geoid_ and Height_
interpolators, except ``GeoidKarney`` and the ``HeigthIDW...`` ones.

Functions and ``LatLon`` methods ``circin6``, ``circum3``, ``circum4_``,
``soddy4``, ``trilaterate3d2`` and ``trilaterate5`` and modules ``auxilats``
and ``rhumbaux`` require numpy_.

Modules ``ellipsoidalGeodSolve`` and ``geodsolve`` and ``azimuthal``
classes ``EquidistantGeodSolve`` and ``GnomonicGeodSolve`` depend on
*Karney*\'s C++ utility GeodSolve_ to be executable and set with env
variable ``PYGEODESY_GEODSOLVE`` or with property ``Ellipsoid.geodsolve``.

To compare ``MGRS`` results from modules ``mgrs`` and ``testMgrs`` with
*Karney*\'s C++ utility GeoConvert_, the latter must be executable and
set with env variable ``PYGEODESY_GEOCONVERT``.

Module ``rhumbsolve`` needs *Karney*\'s C++ utility RhumbSolve_ to
be executable and set with env variable ``PYGEODESY_RHUMBSOLVE`` or
with property ``Ellipsoid.rhumbsolve``.

Documentation
=============

In addition to the ``pygeodesy`` package, the PyGeodesy_ `distribution
files`_ contain the tests, the test results (on macOS only) and the
complete documentation_ generated by Epydoc_ using command line:
``epydoc --html --no-private --no-source --name=PyGeodesy --url=... -v pygeodesy``.

Tests
=====

The tests ran with Python 3.12 (with geographiclib_ 2.0), 3.11.5 (with
geographiclib_ 2.0, numpy_ 1.24.2 and scipy_ 1.10.1), Python 3.10.8 (with
geographiclib_ 2.0, numpy_ 1.23.3, scipy_ 1.9.1, GeoConvert_ 2.2, GeodSolve_
2.2 and RhumbSolve_ 2.2), Python 3.9.6 and Python 2.7.18 (with geographiclib_
1.50, numpy_ 1.16.6, scipy_ 1.2.2, GeoConvert_ 2.2, GeodSolve_ 2.2 and
RhumbSolve_ 2.2), all on macOS 13.5.2 Ventura and in 64-bit only.

All tests ran with and without ``lazy import`` for Python 3 and with command
line option ``-W default`` and env variable ``PYGEODESY_WARNINGS=on`` for all
Python versions.  The results of those tests are included in the distribution
files.

PyPy_ 7.3.12 (Python 3.10.12), Python 3.11.5, 3.10.8 and 3.9.6 run on Apple M1
Silicon (``arm64``), *natively*.  Python 3.8.10 and 2.7.18 run on Intel
(``x86_64``) or Intel *emulation* (\"``arm64_x86_64``\", see function
`pygeodesy.machine`_).

Test coverage has been measured with coverage_ 7.2.2 using only Python
3.11.5 and 3.10.8.  The complete coverage report in HTML and a PDF summary
are included in the distribution files.

The tests also ran with Python 3.11.5 (and geographiclib_ 2.0) on
`Debian 11`_ in 64-bit only and with Python 3.11.5, 3.10.10 and 2.7.18
(all with geographiclib_ 1.52) on `Windows 10`_ in 64- and/or 32-bit.

A single-File and single-Directory application with ``pygeodesy`` has
been bundled using PyInstaller_ 3.4 and 64-bit Python 3.7.4 and 3.7.3
on macOS 10.13.6 High Sierra.

Previously, the tests were run with Python 3.11.2-4, 3.10.1-7, 3.9.1, 3.8.7,
3.7.1, 2.7.15, PyPy_ 7.3.12 (Python 3.10.12), 7.3.1 (Python 3.6.9) and PyPy_
7.1.1 (Python 2.7.13) (and geographiclib_ 1.52, numpy_ 1.16.3, 1.16.4, 1.16.6,
1.19.0, 1.19.4, 1.19.5 or 1.22.4 and scipy_ 1.2.1, 1.4.1, 1.5.2 or 1.8.1) on
`Ubuntu 16.04`_, with Python 3.10.0-1, 3.9.0-5, 3.8.0-6, 3.7.2-6, 3.7.0,
3.6.2-5, 3.5.3, 2.7.13-17, 2.7.10 and 2.6.9 (and numpy_ 1.19.0, 1.16.5, 1.16.2,
1.15.2, 1.14.0, 1.13.1, 1.8.0rc1 or 1.6.2 and scipy_ 1.5.0), PyPy_ 7.3.0 (Python
2.7.13 and 3.6.9), PyPy_ 6.0.0 (Python 2.7.13 and 3.5.3) and `Intel-Python`_
3.5.3 (and numpy_ 1.11.3) on macOS 13.0-4 Ventura, 12.1-6 Monterey,
11.0-5.2-6.1 Big Sur (aka 10.16), 10.15.3, 10.15.5-7 Catalina, 10.14 Mojave,
10.13.6 High Sierra and 10.12 Sierra, MacOS X 10.11 El Capitan and/or MacOS
X 10.10 Yosemite, with Pythonista_ 3.2 (with geographiclib 1.50 or 1.49 and
numpy 1.8.0) on iOS 14.4.2, 11.4.1, 12.0-3 on iPad4, iPhone6, iPhone10 and/or
iPhone12, with Pythonista_ 3.1 on iOS 10.3.3, 11.0.3, 11.1.2 and 11.3 on
iPad4, all in 64-bit only and with 32-bit Python 2.7.14 on Windows Server
2012R2, Windows 10 Pro and 32-bit Python 2.6.6 on Windows XP SP3.

Notes
=====

All Python source code has been statically checked_ with PyChecker_, PyFlakes_,
PyCodeStyle_ (formerly Pep8) and McCabe_ using Python 2.7.18 and with Flake8_
using Python 3.11.5, both in 64-bit on macOS 13.5.2 Ventura.

For a summary of all *Karney*-based functionality in ``pygeodesy``, see
module karney_.

*Last updated: Oct 10, 2023.*

License
=======

``Copyright (C) 2016-2023 -- mrJean1 at Gmail -- All Rights Reserved.``

``Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:``

``The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.``

``THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.``

.. image:: https://Img.Shields.io/pypi/pyversions/PyGeodesy.svg?label=Python
  :target: https://PyPI.org/project/PyGeodesy
.. image:: https://Img.Shields.io/appveyor/ci/mrJean1/PyGeodesy.svg?branch=master&label=AppVeyor
  :target: https://CI.AppVeyor.com/project/mrJean1/PyGeodesy/branch/master
.. image:: https://Img.Shields.io/cirrus/github/mrJean1/PyGeodesy?branch=master&label=Cirrus
  :target: https://Cirrus-CI.com/github/mrJean1/PyGeodesy
.. image:: https://Img.Shields.io/badge/coverage-95%25-brightgreen
  :target: https://GitHub.com/mrJean1/PyGeodesy/blob/master/testcoverage.pdf
.. image:: https://Img.Shields.io/pypi/v/PyGeodesy.svg?label=PyPI
  :target: https://PyPI.org/project/PyGeodesy
.. image:: https://Img.Shields.io/pypi/wheel/PyGeodesy.svg
  :target: https://PyPI.org/project/PyGeodesy/#files
.. image:: https://img.shields.io/pypi/dm/PyGeodesy
  :target: https://PyPI.org/project/PyGeodesy
.. image:: https://Img.Shields.io/pypi/l/PyGeodesy.svg
  :target: https://PyPI.org/project/PyGeodesy

.. _Albers equal-area: https://GeographicLib.SourceForge.io/C++/doc/classGeographicLib_1_1AlbersEqualArea.html
.. _C++ classes: https://GeographicLib.SourceForge.io/C++/doc/annotated.html
.. _C++ GeographicLib: https://GeographicLib.SourceForge.io/C++/doc/index.html
.. _Cartesian: https://mrJean1.GitHub.io/PyGeodesy/docs/pygeodesy-Cartesian-attributes-table.html
.. _Cassini-Soldner: https://GeographicLib.SourceForge.io/C++/doc/classGeographicLib_1_1CassiniSoldner.html
.. _checked: https://GitHub.com/ActiveState/code/tree/master/recipes/Python/546532_PyChecker_postprocessor
.. _Cohen-Sutherland: https://WikiPedia.org/wiki/Cohen-Sutherland_algorithm
.. _coverage: https://PyPI.org/project/coverage
.. _Debian 11: https://Cirrus-CI.com/github/mrJean1/PyGeodesy/master
.. _distribution files: https://GitHub.com/mrJean1/PyGeodesy/tree/master/dist
.. _docs: https://www.Movable-Type.co.UK/scripts/geodesy/docs
.. _documentation: https://mrJean1.GitHub.io/PyGeodesy
.. _ECEF: https://WikiPedia.org/wiki/ECEF
.. _EPSG: https://EPSG.org
.. _Epydoc: https://PyPI.org/project/epydoc
.. _equidistant: https://GeographicLib.SourceForge.io/C++/doc/classGeographicLib_1_1AzimuthalEquidistant.html
.. _Exact: https://GeographicLib.SourceForge.io/C++/doc/classGeographicLib_1_1GeodesicExact.html
.. _Flake8: https://PyPI.org/project/flake8
.. _Forster-Hormann-Popa: https://www.ScienceDirect.com/science/article/pii/S259014861930007X
.. _Fréchet: https://WikiPedia.org/wiki/Frechet_distance
.. _Garefs (GARS): https://WikiPedia.org/wiki/Global_Area_Reference_System
.. _GeoConvert: https://GeographicLib.SourceForge.io/C++/doc/utilities.html
.. _GeodSolve: https://GeographicLib.SourceForge.io/C++/doc/utilities.html
.. _geographiclib: https://PyPI.org/project/geographiclib
.. _Geohashes: https://www.Movable-Type.co.UK/scripts/geohash.html
.. _Geoid: https://mrJean1.GitHub.io/PyGeodesy/docs/pygeodesy.geoids-module.html
.. _Georefs (WGRS): https://WikiPedia.org/wiki/World_Geographic_Reference_System
.. _GitHub: https://GitHub.com/mrJean1/PyGeodesy
.. _GitHub/dist: https://GitHub.com/mrJean1/PyGeodesy/tree/master/dist
.. _Greiner-Hormann: http://www.inf.USI.CH/hormann/papers/Greiner.1998.ECO.pdf
.. _Hausdorff: https://WikiPedia.org/wiki/Hausdorff_distance
.. _Height: https://mrJean1.GitHub.io/PyGeodesy/docs/pygeodesy.heights-module.html
.. _Intel-Python: https://software.Intel.com/en-us/distribution-for-python
.. _interpolate: https://docs.SciPy.org/doc/scipy/reference/interpolate.html
.. _JavaScript originals: https://GitHub.com/ChrisVeness/geodesy
.. _JavaScript source: https://GitHub.com/ChrisVeness/geodesy
.. _John P. Snyder: https://pubs.er.USGS.gov/djvu/PP/PP_1395.pdf
.. _karney: https://mrJean1.GitHub.io/PyGeodesy/docs/pygeodesy.karney-module.html
.. _Latitude/Longitude: https://www.Movable-Type.co.UK/scripts/latlong.html
.. _LatLon: https://mrJean1.GitHub.io/PyGeodesy/docs/pygeodesy-LatLon-attributes-table.html
.. _Liang-Barsky: https://www.CS.Helsinki.FI/group/goa/viewing/leikkaus/intro.html
.. _McCabe: https://PyPI.org/project/mccabe
.. _MGRS: https://GeographicLib.SourceForge.io/C++/doc/classGeographicLib_1_1MGRS.html
.. _MIT License: https://OpenSource.org/licenses/MIT
.. _numpy: https://PyPI.org/project/numpy
.. _numpy array: https://docs.SciPy.org/doc/numpy/reference/generated/numpy.array.html
.. _OSGR: https://www.Movable-Type.co.UK/scripts/latlong-os-gridref.html
.. _3-point resections: https://WikiPedia.org/wiki/Position_resection_and_intersection
.. _PyChecker: https://PyPI.org/project/pychecker
.. _PyCodeStyle: https://PyPI.org/project/pycodestyle
.. _PyFlakes: https://PyPI.org/project/pyflakes
.. _PyGeodesy: https://PyPI.org/project/PyGeodesy
.. _pygeodesy.machine: https://mrJean1.GitHub.io/PyGeodesy/docs/pygeodesy.interns-module.html#machine
.. _PyInstaller: https://PyPI.org/project/pyinstaller
.. _PyPI: https://PyPI.org/project/PyGeodesy
.. _PyPI Download files: https://PyPI.org/project/PyGeodesy/#files
.. _PyPy: https://formulae.brew.sh/formula/pypy3.10
.. _Pythonista: https://OMZ-Software.com/pythonista
.. _Ramer-Douglas-Peucker: https://WikiPedia.org/wiki/Ramer-Douglas-Peucker_algorithm
.. _Reumann-Witkam: https://psimpl.SourceForge.net/reumann-witkam.html
.. _RhumbSolve: https://GeographicLib.SourceForge.io/C++/doc/utilities.html
.. _scipy: https://PyPI.org/project/scipy
.. _simplify: https://Bost.Ocks.org/mike/simplify
.. _Sutherland-Hodgman: https://WikiPedia.org/wiki/Sutherland-Hodgman_algorithm
.. _TRF: http://ITRF.ENSG.IGN.FR
.. _triaxial ellipsoidal: https://GeographicLib.SourceForge.io/1.44/triaxial.html
.. _Ubuntu 16.04: https://Travis-CI.com/mrJean1/PyGeodesy
.. _UPS: https://WikiPedia.org/wiki/Universal_polar_stereographic_coordinate_system
.. _UTM: https://www.Movable-Type.co.UK/scripts/latlong-utm-mgrs.html
.. _Vector-based: https://www.Movable-Type.co.UK/scripts/latlong-vectors.html
.. _Vincenty: https://www.Movable-Type.co.UK/scripts/latlong-vincenty.html
.. _Visvalingam-Whyatt: https://hydra.Hull.ac.UK/resources/hull:8338
.. _Web Mercator: https://WikiPedia.org/wiki/Web_Mercator
.. _Windows 10: https://CI.AppVeyor.com/project/mrJean1/pygeodesy
