ClassesClasses | | Operators

convexityconvexityConvexityConvexity (Operator)

Name

convexityconvexityConvexityConvexity — Shape factor for the convexity of a region.

Signature

convexity(Regions : : : Convexity)

Herror convexity(const Hobject Regions, double* Convexity)

Herror T_convexity(const Hobject Regions, Htuple* Convexity)

void Convexity(const HObject& Regions, HTuple* Convexity)

HTuple HRegion::Convexity() const

static void HOperatorSet.Convexity(HObject regions, out HTuple convexity)

HTuple HRegion.Convexity()

Description

The operator convexityconvexityConvexityConvexityConvexity calculates the convexity of each input region of RegionsRegionsRegionsRegionsregions.

Calculation:

If is the area of the convex hull and the original area of the region the shape factor C is defined as:

The shape factor C is 1 if the region is convex (e.g., rectangle, circle etc.). If there are indentations or holes C is smaller than 1.

In the documentation of this chapter (Regions / Features), you can find an image illustrating regions which vary in their convexity.

In case of an empty region the operator convexityconvexityConvexityConvexityConvexity returns the value 0 (if no other behavior was set (see set_systemset_systemSetSystemSetSystemSetSystem)). If more than one region is passed the numerical values of the contour length are stored in a tuple, the position of a value in the tuple corresponding to the position of the region in the input tuple.

Execution Information

Parameters

RegionsRegionsRegionsRegionsregions (input_object)  region(-array) objectHRegionHRegionHobject

Region(s) to be examined.

ConvexityConvexityConvexityConvexityconvexity (output_control)  real(-array) HTupleHTupleHtuple (real) (double) (double) (double)

Convexity of the input region(s).

Assertion: Convexity <= 1

Result

The operator convexityconvexityConvexityConvexityConvexity returns the value 2 (H_MSG_TRUE) if the input is not empty. The behavior in case of empty input (no input regions available) is set via the operator set_system('no_object_result',<Result>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>). The behavior in case of empty region (the region is the empty set) is set via set_system('empty_region_result',<Result>)set_system("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>). If necessary an exception is raised.

Possible Predecessors

thresholdthresholdThresholdThresholdThreshold, regiongrowingregiongrowingRegiongrowingRegiongrowingRegiongrowing, connectionconnectionConnectionConnectionConnection

See also

select_shapeselect_shapeSelectShapeSelectShapeSelectShape, area_centerarea_centerAreaCenterAreaCenterAreaCenter, shape_transshape_transShapeTransShapeTransShapeTrans

Module

Foundation


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