momepy.shape_index¶

momepy.shape_index(geometry, longest_axis_length=None)[source]¶

Calculates the shape index of each object given its geometry.

\[{\sqrt{{area} \over {\pi}}} \over {0.5 * \textit{longest axis}}\]

Parameters:¶

geometry : GeoDataFrame | GeoSeries¶

A GeoDataFrame or GeoSeries containing polygons to analyse.

longest_axis_length : NDArray[np.float64] | Series | None, optional¶

array of longest axis lengths. If None, it will be calculated, by default None

Return type:¶

Series

Examples

>>> path = momepy.datasets.get_path("bubenec")
>>> buildings = geopandas.read_file(path, layer="buildings")
>>> momepy.shape_index(buildings)
0      0.756403
1      0.624834
2      0.767028
3      0.721395
4      0.768958
        ...
139    0.750622
140    0.725074
141    0.636296
142    0.728289
143    0.797739
Length: 144, dtype: float64

If you know the longest axis length, you can pass it to skip the computation step.

>>> lal = momepy.longest_axis_length(buildings)
>>> momepy.shape_index(buildings, longest_axis_length=lal)
0      0.756403
1      0.624834
2      0.767028
3      0.721395
4      0.768958
        ...
139    0.750622
140    0.725074
141    0.636296
142    0.728289
143    0.797739
Length: 144, dtype: float64