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TEMP: remove overlay docs to check speedup

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Joris Van den Bossche
2016-06-06 21:53:08 +02:00
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@@ -18,63 +18,6 @@ The basic idea is demonstrated by the graphic below but keep in mind that overla
(Note to users familiar with the *shapely* library: ``overlay`` can be thought of as offering versions of the standard *shapely* set-operations that deal with the complexities of applying set operations to two *GeoSeries*. The standard *shapely* set-operations are also available as ``GeoSeries`` methods.)
Overlay Example
-----------------
First, we load some example data:
.. ipython:: python
world = gpd.read_file(gpd.datasets.get_path('naturalearth_lowres'))
capitals = gpd.read_file(gpd.datasets.get_path('naturalearth_cities'))
# Select some columns
countries = world[['geometry', 'name']]
# Project to crs that uses meters as distance measure
countries = countries.to_crs('+init=epsg:3395')[countries.name!="Antarctica"]
capitals = capitals.to_crs('+init=epsg:3395')
To illustrate the ``overlay`` function, consider the following case in which one wishes to identify the "core" portion of each country -- defined as areas within 500km of a capital -- using a ``GeoDataFrame`` of countries and a ``GeoDataFrame`` of capitals.
.. ipython:: python
# Look at countries:
@savefig world_basic.png width=5in
countries.plot();
# Now buffer cities to find area within 500km.
# Check CRS -- World Mercator, units of meters.
capitals.crs
# make 500km buffer
capitals['geometry']= capitals.buffer(500000)
@savefig capital_buffers.png width=5in
capitals.plot();
To select only the portion of countries within 500km of a capital, we specify the ``how`` option to be "intersect", which creates a new set of polygons where these two layers overlap:
.. ipython:: python
country_cores = gpd.overlay(countries, capitals, how='intersection')
@savefig country_cores.png width=5in
country_cores.plot();
Changing the "how" option allows for different types of overlay operations. For example, if we were interested in the portions of countries *far* from capitals (the peripheries), we would compute the difference of the two.
.. ipython:: python
country_peripheries = gpd.overlay(countries, capitals, how='difference')
@savefig country_peripheries.png width=5in
country_peripheries.plot();
More Examples
-----------------
A larger set of examples of the use of ``overlay`` can be found `here <http://nbviewer.jupyter.org/github/geopandas/geopandas/blob/master/examples/overlays.ipynb>`_
.. toctree::
:maxdepth: 2