geopandas.GeoSeries.maximum_inscribed_circle

GeoSeries.maximum_inscribed_circle(*, tolerance=None)

Returns a GeoSeries of geometries representing the largest circle that is fully contained within the input geometry.

Constructs the “maximum inscribed circle” (MIC) for a polygonal geometry, up to a specified tolerance. The MIC is determined by a point in the interior of the area which has the farthest distance from the area boundary, along with a boundary point at that distance. In the context of geography the center of the MIC is known as the “pole of inaccessibility”. A cartographic use case is to determine a suitable point to place a map label within a polygon. The radius length of the MIC is a measure of how “narrow” a polygon is. It is the distance at which the negative buffer becomes empty.

The method supports polygons with holes and multipolygons but will raise an error for any other geometry type.

Returns a GeoSeries with two-point linestrings rows, with the first point at the center of the inscribed circle and the second on the boundary of the inscribed circle.

Requires Shapely >= 2.1.

Added in version 1.1.0.

Parameters:

tolerancefloat, np.array, pd.Series

Stop the algorithm when the search area is smaller than this tolerance. When not specified, uses max(width, height) / 1000 per geometry as the default. If np.array or pd.Series are used then it must have same length as the GeoSeries.

See also

minimum_bounding_circle

Examples

>>> from shapely.geometry import Polygon, LineString, Point
>>> s = geopandas.GeoSeries(
...     [
...         Polygon([(0, 0), (1, 1), (0, 1), (0, 0)]),
...         Polygon([(0, 0), (10, 10), (0, 10), (0, 0)]),
...     ]
... )
>>> s
0       POLYGON ((0 0, 1 1, 0 1, 0 0))
1    POLYGON ((0 0, 10 10, 0 10, 0 0))
dtype: geometry

>>> s.maximum_inscribed_circle()
0    LINESTRING (0.29297 0.70703, 0.5 0.5)
1        LINESTRING (2.92969 7.07031, 5 5)
dtype: geometry

>>> s.maximum_inscribed_circle(tolerance=2)
0    LINESTRING (0.25 0.5, 0.375 0.375)
1          LINESTRING (2.5 7.5, 2.5 10)
dtype: geometry