libpysal.cg.voronoi_frames¶

libpysal.cg.
voronoi_frames
(points, radius=None, clip='extent')[source]¶ Composite helper to return Voronoi regions and generator points as individual dataframes.
 Parameters
 pointsarray_like
The originator points.
 radius
float
The distance to “points at infinity” used in building voronoi cells.
 clip
str
,shapely.geometry.Polygon
An overloaded option about how to clip the voronoi cells. The options are:
‘none’/None: No clip is applied. Voronoi cells may be arbitrarily larger that the source map. Note that this may lead to cells that are many orders of magnitude larger in extent than the original map. Not recommended.
‘bbox’/’extent’/’bounding box’: Clip the voronoi cells to the bounding box of the input points.
‘chull’/’convex hull’: Clip the voronoi cells to the convex hull of the input points.
‘ashape’/’ahull’: Clip the voronoi cells to the tightest hull that contains all points (e.g. the smallest alphashape, using
libpysal.cg.alpha_shape_auto
).Polygon: Clip to an arbitrary Polygon.
 tolerance
float
The percent of map width to use to buffer the extent of the map, if clipping (default: .01, or 1 percent).
 Returns
 reg_vtx
tuple
Two
geopandas.GeoDataFrame
(orpandas.DataFrame
ifgeopandas
is unavailable) objects–(region_df, points_df)
–of finite Voronoi polygons and the originator points as geometries.
 reg_vtx
Notes
If
geopandas
is not available the return types will bepandas.DataFrame
objects, each with a geometry column populated with PySAL shapes. Ifgeopandas
is available, return types arepandas.GeoDataFrame
objects with a geometry column populated with shapely geometry types.Examples
>>> points = [(10.2, 5.1), (4.7, 2.2), (5.3, 5.7), (2.7, 5.3)] >>> regions_df, points_df = voronoi_frames(points) >>> regions_df.shape (4, 1) >>> regions_df.shape == points_df.shape True