geopandas.GeoSeries.sample_points

GeoSeries.sample_points(size, method='uniform', seed=None, rng=None, **kwargs)

Sample points from each geometry.

Generate a MultiPoint per each geometry containing points sampled from the geometry. You can either sample randomly from a uniform distribution or use an advanced sampling algorithm from the pointpats package.

For polygons, this samples within the area of the polygon. For lines, this samples along the length of the linestring. For multi-part geometries, the weights of each part are selected according to their relevant attribute (area for Polygons, length for LineStrings), and then points are sampled from each part.

Any other geometry type (e.g. Point, GeometryCollection) is ignored, and an empty MultiPoint geometry is returned.

Parameters:

sizeint | array-like

The size of the sample requested. Indicates the number of samples to draw from each geometry. If an array of the same length as a GeoSeries is passed, it denotes the size of a sample per geometry.

methodstr, default “uniform”

The sampling method. uniform samples uniformly at random from a geometry using numpy.random.uniform. Other allowed strings (e.g. "cluster_poisson") denote sampling function name from the pointpats.random module (see http://pysal.org/pointpats/api.html#random-distributions). Pointpats methods are implemented for (Multi)Polygons only and will return an empty MultiPoint for other geometry types.

rng{None, int, array_like[ints], SeedSequence, BitGenerator, Generator}, optional

A random generator or seed to initialize the numpy BitGenerator. If None, then fresh, unpredictable entropy will be pulled from the OS.

**kwargsdict

Options for the pointpats sampling algorithms.

Returns:

GeoSeries

Points sampled within (or along) each geometry.

Examples

>>> from shapely.geometry import Polygon
>>> s = geopandas.GeoSeries(
...     [
...         Polygon([(1, -1), (1, 0), (0, 0)]),
...         Polygon([(3, -1), (4, 0), (3, 1)]),
...     ]
... )

>>> s.sample_points(size=10)  
0    MULTIPOINT (0.04783 -0.04244, 0.24196 -0.09052...
1    MULTIPOINT (3.00672 -0.52390, 3.01776 0.30065,...
Name: sampled_points, dtype: geometry