cartagen.boffet_areas

boffet_areas(buildings, buffer, erosion, simplification_distance=2.0)

Calculate urban areas from buildings.

This algorithm proposed by Boffet [1] uses buffer around the buildings, then simplify and erode the unioned result to characterize urban areas.

Parameters:

• polygons (list of Polygon) – Buildings to generate the urban area from.

• buffer (float) – The buffer size used to merge buildings that are close from each other.

• erosion (float) – The erosion size to avoid the urban area to expand too far from the buildings located on the edge.

• simplification_distance (float, optional) – The distance threshold used by the Douglas-Peucker simplification on the edge.

Returns:

list of Polygon

See also

amalgamate_buildings_morphological

Amalgamate buildings using dilation and erosion. Useful for larger scale maps.

References

[1]

Annabelle Boffet. Généralisation cartographique et description des espaces urbains. In Bulletin de l’Association de Géographes Français. 2003. URL: https://api.semanticscholar.org/CorpusID:118066053.

Examples

>>> buildings = [Polygon([(1, 0), (9, 0), (9, 6), (1, 6), (1, 0)]), Polygon([(10, 0), (17, 0), (17, 6), (10, 6), (10, 0)])]
>>> boffet_areas(buildings, 2.0, 1.0)
<[<POLYGON ((-0.909 5.627, 17.078 7.784, 18.66 -0.02, 0.874 -1.782, -0.909 5.6...>]>

(Source code)