cartagen.simplify_li_openshaw

simplify_li_openshaw(geometry, cell_size, preserve_extremities=True)

Simplify a line or a polygon using a regular grid.

This algorithm proposed by Li & Openshaw [1] simplifies lines based on a regular square grid. It first divide the line vertexes into groups partionned by a regular grid, then each group of vertexes is replaced by their centroid.

Parameters:

• geometry (LineString, MultiLineString, Polygon, MultiPolygon, LinearRing) – The geometry to simplify.

• cell_size (float) – The size of the regular grid used to divide the line.

• preserve_extremities (bool, optional) – Whether the algorithm should preserve the first and last vertex of the input geometry.

Returns:

LineString, MultiLineString, Polygon, MultiPolygon, LinearRing

See also

simplify_angular

Simplify a line or polygon by removing vertexes with small angles.

simplify_douglas_peucker

Simplify a line or polygon using a distance-based selection.

simplify_lang

Simplify a line or polygon using a look-ahead distance-based selection.

simplify_raposo

Simplify a line or a polygon using an hexagonal tessellation.

simplify_reumann_witkam

Simplify a line or polygon using a directional distance-based selection.

simplify_visvalingam_whyatt

Simplify a line or polygon using an area-based selection.

simplify_wang_muller

Simplify a line or polygon using a bend-reduction method.

simplify_whirlpool

Simplify a line or polygon using an epsilon-circle based selection.

References

[1]

Zhilin Li and Stan Openshaw. A natural principle for the objective generalization of digital maps. In Computer Science, Geography. 1993. URL: https://api.semanticscholar.org/CorpusID:120732702.

Examples

>>> line = LineString([(0, 0), (1, 1), (2, 0), (5, 3)])
>>> c4.simplify_li_openshaw(line, 1)
<LINESTRING (0 0, 0.5 0.5, 2 0, 5 3)>

(Source code)