geos.GEOSConcaveHull ⇒ GEOSGeometry ⏏
Returns a "concave hull" of a geometry. A concave hull is a polygon which contains all the points of the input, but is a better approximation than the convex hull to the area occupied by the input. Frequently used to convert a multi-point into a polygonal area. that contains all the points in the input Geometry.
Kind: global property of geos
Returns: GEOSGeometry - A newly allocated geometry of the concave hull. NULL on exception.
| Param | Type | Description |
|---|---|---|
| g | GEOSGeometry | The input geometry |
| ratio | number | The edge length ratio value, between 0 and 1. |
| allowHoles | number | When non-zero, the polygonal output may contain holes. |
geos.GEOSConcaveHullByLength ⇒ GEOSGeometry ⏏
Returns a "concave hull" of a geometry. A concave hull is a polygon which contains all the points of the input, but is a better approximation than the convex hull to the area occupied by the input. Frequently used to convert a multi-point into a polygonal area. that contains all the points in the input Geometry.
Kind: global property of geos
Returns: GEOSGeometry - A newly allocated geometry of the concave hull. NULL on exception.
| Param | Type | Description |
|---|---|---|
| g | GEOSGeometry | The input geometry |
| length | number | The maximum edge length (0 or greater) |
| allowHoles | number | When non-zero, the polygonal output may contain holes. |
geos.GEOSConcaveHullByLength_r ⇒ GEOSGeometry ⏏
Returns a "concave hull" of a geometry. A concave hull is a polygon which contains all the points of the input, but is a better approximation than the convex hull to the area occupied by the input. Frequently used to convert a multi-point into a polygonal area. that contains all the points in the input Geometry.
Kind: global property of geos
Returns: GEOSGeometry - A newly allocated geometry of the concave hull. NULL on exception.
| Param | Type | Description |
|---|---|---|
| handle | GEOSContextHandle_t | - |
| g | GEOSGeometry | The input geometry |
| ratio | number | The maximum edge length (0 or greater) |
| allowHoles | number | When non-zero, the polygonal output may contain holes. |
geos.GEOSConcaveHullOfPolygons ⇒ GEOSGeometry ⏏
Constructs a concave hull of a set of polygons, respecting the polygons as constraints.
Kind: global property of geos
Returns: GEOSGeometry - A newly allocated geometry of the concave hull. NULL on exception.
| Param | Type | Description |
|---|---|---|
| g | GEOSGeometry | the valid MultiPolygon geometry to process |
| lengthRatio | number | specifies the Maximum Edge Length as a fraction of the difference between the longest and shortest edge lengths between the polygons. This normalizes the Maximum Edge Length to be scale-free. A value of 1 produces the convex hull; a value of 0 produces the original polygons. |
| isTight | number | is the concave hull allowed to contain holes? |
| isHolesAllowed | number | does the hull follow the outer boundaries of the input polygons. |
geos.GEOSConcaveHullOfPolygons_r ⇒ GEOSGeometry ⏏
Constructs a concave hull of a set of polygons, respecting the polygons as constraints.
Kind: global property of geos
Returns: GEOSGeometry - A newly allocated geometry of the concave hull. NULL on exception.
| Param | Type | Description |
|---|---|---|
| handle | GEOSContextHandle_t | - |
| g | GEOSGeometry | the valid MultiPolygon geometry to process |
| lengthRatio | number | specifies the Maximum Edge Length as a fraction of the difference between the longest and shortest edge lengths between the polygons. This normalizes the Maximum Edge Length to be scale-free. A value of 1 produces the convex hull; a value of 0 produces the original polygons. |
| isTight | number | is the concave hull allowed to contain holes? |
| isHolesAllowed | number | does the hull follow the outer boundaries of the input polygons. |
geos.GEOSConcaveHull_r ⇒ GEOSGeometry ⏏
Returns a "concave hull" of a geometry. A concave hull is a polygon which contains all the points of the input, but is a better approximation than the convex hull to the area occupied by the input. Frequently used to convert a multi-point into a polygonal area. that contains all the points in the input Geometry.
Kind: global property of geos
Returns: GEOSGeometry - A newly allocated geometry of the concave hull. NULL on exception.
| Param | Type | Description |
|---|---|---|
| handle | GEOSContextHandle_t | - |
| g | GEOSGeometry | The input geometry |
| ratio | number | The edge length ratio value, between 0 and 1. |
| allowHoles | number | When non-zero, the polygonal output may contain holes. |