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geos.GEOSPolygonHullSimplify ⇒ GEOSGeometry

Computes a boundary-respecting hull of a polygonal geometry, with hull shape determined by a target parameter specifying the fraction of the input vertices retained in the result. Larger values produce less concave results. A value of 1 produces the convex hull; a value of 0 produces the original geometry. An outer hull is computed if the parameter is positive, an inner hull is computed if it is negative.

Kind: global property of geos
Returns: GEOSGeometry - A newly allocated geometry of the concave hull. NULL on exception.

ParamTypeDescription
gGEOSGeometrythe polygonal geometry to process
isOuternumberindicates whether to compute an outer or inner hull (1 for outer hull, 0 for inner)
vertexNumFractionnumberthe target fraction of the count of input vertices to retain in result

geos.GEOSPolygonHullSimplifyMode ⇒ GEOSGeometry

Computes a topology-preserving simplified hull of a polygonal geometry, with hull shape determined by the parameter, controlled by a parameter mode, which is one defined in GEOSPolygonHullParameterModes. Larger values compute less concave results and a value of 0 produces the original geometry. Either outer or inner hulls can be computed.

Kind: global property of geos
Returns: GEOSGeometry - A newly allocated geometry of the concave hull. NULL on exception.

ParamTypeDescription
gGEOSGeometrythe polygonal geometry to process
isOuternumberindicates whether to compute an outer or inner hull (1 for outer hull, 0 for inner)
parameterModenumberthe interpretation to apply to the parameter argument; see GEOSPolygonHullParameterModes
parameternumberthe target ratio of area difference to original area

geos.GEOSPolygonHullSimplifyMode_r ⇒ GEOSGeometry

Computes a topology-preserving simplified hull of a polygonal geometry, with hull shape determined by the parameter, controlled by a parameter mode, which is one defined in GEOSPolygonHullParameterModes. Larger values compute less concave results and a value of 0 produces the original geometry. Either outer or inner hulls can be computed.

Kind: global property of geos
Returns: GEOSGeometry - A newly allocated geometry of the concave hull. NULL on exception.

ParamTypeDescription
handleGEOSContextHandle_t-
gGEOSGeometrythe polygonal geometry to process
isOuternumberindicates whether to compute an outer or inner hull (1 for outer hull, 0 for inner)
parameterModenumberthe interpretation to apply to the parameter argument; see GEOSPolygonHullParameterModes
parameternumberthe target ratio of area difference to original area

geos.GEOSPolygonHullSimplify_r ⇒ GEOSGeometry

Computes a boundary-respecting hull of a polygonal geometry, with hull shape determined by a target parameter specifying the fraction of the input vertices retained in the result. Larger values produce less concave results. A value of 1 produces the convex hull; a value of 0 produces the original geometry. An outer hull is computed if the parameter is positive, an inner hull is computed if it is negative.

Kind: global property of geos
Returns: GEOSGeometry - A newly allocated geometry of the concave hull. NULL on exception.

ParamTypeDescription
handleGEOSContextHandle_t-
gGEOSGeometrythe polygonal geometry to process
isOuternumberindicates whether to compute an outer or inner hull (1 for outer hull, 0 for inner)
vertexNumFractionnumberthe target fraction of the count of input vertices to retain in result