cartogram_geopandas

v0.0.0c

Fast and convenient creation of continuous cartogram on a Polygon/MultiPolygon GeoDataFrame (modify the geometry in place or create a new GeoDataFrame).

Code adapted from Carson Farmer code (https://github.com/carsonfarmer/cartogram : former code used in 'Cartogram' QGis python plugin) to fit the geopandas.GeoDataFrame datastructure. Carson Farmer's code is partially related to 'pyCartogram.py' from Eric Wolfs. Algorithm itself based on : Dougenik, J. A, N. R. Chrisman, and D. R. Niemeyer. 1985. "An algorithm to construct continuous cartograms." Professional Geographer 37:75-81

Early stage of developement / mainly untested. No warranty of any kind concerning the result.

Requirements

• Cython

Installation

$ git clone https://github.com/mthh/cartogram_geopandas.git
$ cd cartogram_geopandas/
$ python setup.py install

Usage

In [1]: import geopandas as gpd

In [2]: geodf = gpd.read_file('datasource.shp')

In [3]: from cartogram_geopandas import make_cartogram

In [4]: transformed_geodf = make_cartogram(geodf, 'Field_to_use', 4, inplace=False)  # 4 = number of iterations

In [5]: geodf.plot()
Out[5]: <matplotlib.axes._subplots.AxesSubplot at 0x7fa76932f470>

In [6]: transformed_geodf.plot()
Out[6]: <matplotlib.axes._subplots.AxesSubplot at 0x7fa7478dba90>

Todo

• Probably a lot of things (properly handling crs, increasing computation speed, etc.)

Copyright (C) 2015 mthh Copyright (C) 2013 Carson Farmer