cldfgeojson 1.0.0

Functionality to access and curate GeoJSON in CLDF datasets

cldfgeojson

cldfgeojson provides tools to work with geographic data structures encoded as GeoJSON in the context of CLDF datasets.

Install

pip install cldfgeojson

Creating CLDF datasets with speaker area data in GeoJSON

The functionality in cldfgeojson.create helps adding speaker area information when creating CLDF datasets (e.g. with cldfbench).

Working around Antimeridian problems

Tools like shapely allow doing geometry with shapes derived from GeoJSON, e.g. computing intersections or centroids. But shapely considers coordinates to be in the cartesian plane rather than on the surface of the earth. While this works generally well enough close to the equator, it fails for geometries crossing the antimeridian. To prepare GeoJSON objects for investigation with shapely, we provide a function that "moves" objects on a - somewhat linguistically informed - pacific-centered cartesian plane: longitudes less than 26°W are adapted by adding 360°, basically moving the interval of valid longitudes from -180°..180° to -26°..334°. While this just moves the antimeridian problems to 26°W, it's still useful because most spatial data about languages does not cross 26°W - which cannot be said for 180°E because this longitude is crosssed by the speaker area of the Austronesian family.

>>> from cldfgeojson.geojson import pacific_centered
>>> from shapely.geometry import shape
>>> p1 = shape({"type": "Point", "coordinates": [179, 0]})
>>> p2 = shape({"type": "Point", "coordinates": [-179, 0]})
>>> p1.distance(p2)
358.0
>>> p1 = shape(pacific_centered({"type": "Point", "coordinates": [179, 0]}))
>>> p2 = shape(pacific_centered({"type": "Point", "coordinates": [-179, 0]}))
>>> p1.distance(p2)
2.0

Manipulating geo-referenced images in GeoTIFF format

The cldfgeojson.geotiff module provides functionality related to images in GeoTIFF format.

Commandline interface

cldfgeojson also provides cldfbench sub-commands:

• geojson.webmercator
• geojson.overlay

leaflet.draw

This package contains the leaflet.draw plugin in the form of data:// URLs in a mako template. leaflet.draw is distributed under a MIT license:

Copyright 2012-2017 Jon West, Jacob Toye, and Leaflet

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.