utm-no-numpy 0.7.2.11

Bidirectional UTM-WGS84 converter for python

Bidirectional UTM-WGS84 converter for python.

Utm optionally requires numpy, but in Pythonic EAFFTP style, always attempts to import it even when it is not installed. Utm itself is otherwise a pure Python package, and is also popular in environments (e.g. Rhino/Grasshopper) that do not support C extensions such as numpy. It even already has alternative code to use when numpy cannot be imported.

In one of those environments the multitude of user plug-ins, the ad-hoc import system, and the design of 3rd party plug-ins, can easily cause dependency conflicts. One such plug-in added a directory of CPython 3 C extensions, including numpy, to IronPython 2.7’s sys.path, causing the normal utm to crash.

This fork of utm does not try to fix the world; it simply removes utm’s attempt to import numpy.

Usage

>>> import utm_no_numpy as utm

Latitude/Longitude to UTM

Convert a (latitude, longitude) tuple into an UTM coordinate:

>>> utm.from_latlon(51.2, 7.5)
(395201.3103811303, 5673135.241182375, 32, 'U')

The syntax is utm.from_latlon(LATITUDE, LONGITUDE).

The return has the form (EASTING, NORTHING, ZONE_NUMBER, ZONE_LETTER).

UTM to Latitude/Longitude

Convert an UTM coordinate into a (latitude, longitude) tuple:

>>> utm.to_latlon(340000, 5710000, 32, 'U')
(51.51852098408468, 6.693872395145327)

The syntax is utm.to_latlon(EASTING, NORTHING, ZONE_NUMBER, ZONE_LETTER).

The return has the form (LATITUDE, LONGITUDE).

Since the zone letter is not strictly needed for the conversion you may also the northern parameter instead, which is a named parameter and can be set to either True or False. Have a look at the unit tests to see how it can be used.

The UTM coordinate system is explained on this Wikipedia page.

Speed

The library has been compared to the more generic pyproj library by running the unit test suite through pyproj instead of utm. These are the results:

• with pyproj (without projection cache): 4.0 - 4.5 sec

• with pyproj (with projection cache): 0.9 - 1.0 sec

• with utm: 0.4 - 0.5 sec

Development

Create a new virtualenv and install the library via pip install -e .. After that install the pytest package via pip install pytest and run the unit test suite by calling pytest.

Changelog

see CHANGELOG.rst file

Authors

• Bart van Andel <[e-mail]>

• Tobias Bieniek <[e-mail]>

• Torstein I. Bø

License

Copyright (C) 2012 Tobias Bieniek <[e-mail]>

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.