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

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

Transcribed from `JavaScript originals`_ by *Chris Veness (C) 2005-2019*
and several `C++ classes`_ by *Charles F.F. Karney (C) 2008-2020* and
published under the same `MIT License`_.

There are three modules for ellipsoidal earth models, *ellipsoidalKarney*,
*-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, path intersections, 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 the Python `geographiclib`_
and `C++ GeographicLib`_.

Also included are modules for conversions to and from `Cassini-Soldner`_,
ECEF_ (Earth-Centered, Earth-Fixed cartesian), UPS_ (Universal Polar
Stereographic), UTM_ (Exact_ and Universal Transverse Mercator) and
`Web Mercator`_ (Pseudo-Mercator) coordinates, MGRS_ (NATO Military Grid
Reference System) 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, azimuthal projections
and Lambert conformal conic projections and positions (from `John P. Snyder`_,
*Map Projections -- A Working Manual*, 1987), functions to clip a path or polygon
of *LatLon* points using the `Cohen-Sutherland`_, the `Liang–Barsky`_ and the
`Sutherland-Hodgman`_ methods, functions to simplify_ or linearize a path of
*LatLon* points (or a `numpy array`_), including implementations of the
`Ramer-Douglas-Peucker`_, the `Visvalingam-Whyatt`_ and the `Reumann-Witkam`_
algorithms and modified versions of the former.  Other classes interpolate_
the *height* of *LatLon* points and several *Geoid* models or compute various
`Fréchet`_ or Hausdorff_ distances.

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

To install PyGeodesy, type ``pip install PyGeodesy`` or ``easy_install
PyGeodesy`` in a terminal or command window.

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] setup.py test`` or type
``python[3] test/run.py`` or type ``python[3] test/unitTestSuite.py``
before or after installation.

Installation of `geographiclib`_, `numpy`_ and `scipy`_ is optional.
However, the former is required to use classes *EquidistantKarney*,
*GnomonicKarney*, *CassiniSoldner* and *Css* and function *toCss*, for
module *ellipsoidalKarney* classes *LatLon* and *Cartesian* and
functions *areaOf*, *intersections2* and *perimeterOf* and for the
*HeightIDWkarney* interpolator.  Both the latter are needed for
most *Geoid...* and *Height...* interpolator classes, but not for the
other *HeigthIDW...* ones.

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 have been run with Python 3.9.1 (with geographiclib_ 1.50),
Python 3.8.6 (with geographiclib_ 1.50, numpy_ 1.19.2 and scipy_ 1.5.2)
and macOS' Python 2.7.16 (with numpy_ 1.16.6), all on macOS 11.1 (10.16)
Big Sur and all in 64-bit only.  The tests run with and without ``lazy
import`` for Python 3 and with C{-W error} for all Python versions.  The
results of those tests are included in the distribution files.

Test coverage has been measured with coverage_ 4.5.4 using Python 3.9.1
(with geographiclib_ 1.50), Python 3.8.6 (with geographiclib_ 1.50, numpy_
1.19.2 and scipy_ 1.5.2) and macOS' Python 2.7.16 (with numpy_ 1.16.6).
The complete coverage report in HTML and a PDF summary are included in
the distribution files.

The tests also ran with Python 3.8.0, 3.7.1, 3.6.7, 2.7.15 and PyPy_
7.1.1 (Python 3.6.1 and 2.7.13) (and geographiclib_ 1.50 or 1.49) on
`Ubuntu 14.04`_ and with Python 3.9.1 (and geographiclib_ 1.50 or
1.49) on `Debian 9`_, all in 64-bit only and with Python 3.8.0, 3.7.5
and 2.7.17 (all with geographiclib_ 1.50 or 1.49) on `Windows Server
2012R2`_ in both 64- and 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 3.8.0-5, 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 10.15.3,
10.15.5-7 Catalina, macOS 10.14 Mojave, macOS 10.13.6 High Sierra, macOS
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 11.4.1, 12.0-3 on iPad4, iPhone6 and/or iPhone10, 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 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 3.9.1, both in 64-bit on macOS 11.1 (10.16)
Big Sur.

Classes with a name ending in ``-Karney`` and several more are transcribed
from *Karney*'s `C++ classes`_ or require *Karney*'s geographiclib_ package
to be installed.  A complete list is in module karney_.

Some function and method names differ from the JavaScript version.  In such
cases documentation tag **JS name:** shows the original JavaScript name.

*Last updated: Jan 31, 2021.*

License
=======

``Copyright (C) 2016-2021 -- 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/travis/mrJean1/PyGeodesy.svg?branch=master&label=Travis
  :target: https://Travis-CI.com/mrJean1/PyGeodesy
.. image:: https://Img.Shields.io/badge/coverage-96%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/l/PyGeodesy.svg
  :target: https://PyPI.org/project/PyGeodesy

.. _Albers Equal-Area: https://GeographicLib.SourceForge.io/html/classGeographicLib_1_1AlbersEqualArea.html
.. _C++ classes: https://GeographicLib.SourceForge.io/html/annotated.html
.. _C++ GeographicLib: https://GeographicLib.SourceForge.io/html/index.html
.. _Cartesian: https://mrJean1.GitHub.io/PyGeodesy/docs/pygeodesy-Cartesian-attributes-table.html
.. _Cassini-Soldner: https://GeographicLib.SourceForge.io/html/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 9: 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://www.EPSG-Registry.org
.. _Epydoc: https://PyPI.org/project/epydoc
.. _Exact: https://GeographicLib.SourceForge.io/html/classGeographicLib_1_1TransverseMercatorExact.html
.. _Flake8: https://PyPI.org/project/flake8
.. _Fréchet: https://WikiPedia.org/wiki/Frechet_distance
.. _Garefs (GARS): https://WikiPedia.org/wiki/Global_Area_Reference_System
.. _geographiclib: https://PyPI.org/project/geographiclib
.. _Geohashes: https://www.Movable-Type.co.UK/scripts/geohash.html
.. _Georefs (WGRS): https://WikiPedia.org/wiki/World_Geographic_Reference_System
.. _GitHub: https://GitHub.com/mrJean1/PyGeodesy
.. _Hausdorff: https://WikiPedia.org/wiki/Hausdorff_distance
.. _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://www.Movable-Type.co.UK/scripts/latlong-utm-mgrs.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
.. _PyChecker: https://PyPI.org/project/pychecker
.. _PyCodeStyle: https://PyPI.org/project/pycodestyle
.. _PyFlakes: https://PyPI.org/project/pyflakes
.. _PyGeodesy: https://PyPI.org/project/PyGeodesy
.. _PyInstaller: https://www.PyInstaller.org
.. _PyPI: https://PyPI.org/project/PyGeodesy
.. _PyPy: https://PyPy.org
.. _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
.. _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
.. _Ubuntu 14.04: 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 Server 2012R2: https://CI.AppVeyor.com/project/mrJean1/pygeodesy
