geos.GEOSMaximumInscribedCircle ⇒ GEOSGeometry
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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 class supports polygons with holes and multipolygons. The implementation uses a successive-approximation technique over a grid of square cells covering the area geometry. The grid is refined using a branch-and-bound algorithm. Point containment and distance are computed in a performant way by using spatial indexes. Returns a two-point linestring, with one point at the center of the inscribed circle and the other on the boundary of the inscribed circle.
Kind: global property of geos
Returns: GEOSGeometry
- A newly allocated geometry of the MIC. NULL on exception. Caller is responsible for freeing with GEOSGeom_destroy().
Param | Type | Description |
---|---|---|
g | GEOSGeometry | Input geometry |
tolerance | number | Stop the algorithm when the search area is smaller than this tolerance |
geos.GEOSMaximumInscribedCircle_r ⇒ GEOSGeometry
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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 class supports polygons with holes and multipolygons. The implementation uses a successive-approximation technique over a grid of square cells covering the area geometry. The grid is refined using a branch-and-bound algorithm. Point containment and distance are computed in a performant way by using spatial indexes. Returns a two-point linestring, with one point at the center of the inscribed circle and the other on the boundary of the inscribed circle.
Kind: global property of geos
Returns: GEOSGeometry
- A newly allocated geometry of the MIC. NULL on exception. Caller is responsible for freeing with GEOSGeom_destroy().
Param | Type | Description |
---|---|---|
handle | GEOSContextHandle_t | - |
g | GEOSGeometry | Input geometry |
tolerance | number | Stop the algorithm when the search area is smaller than this tolerance |