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PolygonCircularity

Header:	FIL.h
Namespace:	fil
Module:	FoundationBasic

Computes the area of a polygon divided by the area of a circle having the same feature.

Syntax

void fil::PolygonCircularity
(
	const fil::Path& inPolygon,
	const fil::CircularityMeasure::Type inCircularityMeasure,
	float& outCircularity
)

Parameters

Name	Type	Default
inPolygon	const Path&
inCircularityMeasure	const CircularityMeasure::Type	RadiusPreserving
outCircularity	float&

Description

Circularity is a measure of similarity of a polygon to the perfect circle. Circular polygons have circularity close to 1.0, while the more elongated the shape is (or contains more holes), the closer to 0.0 is its circularity.

Mathematically, the circularity is calculated as follows: Where c denotes a circular polygon having the same feature as input polygon s. The feature being considered depends on the inCircularityMeasure chosen and it is:

the minimal bounding circle in case of BoundingCirclePreserving
the perimeter in case of PerimeterPreserving
the radius (maximal distance from mass center to any of the shape points) in case of RadiusPreserving

Note that if the input path is not a valid polygon (i.e. it has at least one self-intersection), the computation may lead to results that are not intuitive.

Examples

Circularity with RadiusPreserving of the sample polygon equals to 0.340.

Circularity with PerimeterPreserving of the sample polygon equals to 0.998.

Errors

List of possible exceptions: