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PolygonElongation


Header: FIL.h
Namespace: fil
Module: FoundationBasic

Computes the elongation factor of a polygon (perfect circle has minimal elongation equal 1.0).

Syntax

C++
C#
 
void fil::PolygonElongation
(
	const fil::Path& inPolygon,
	float& outElongation
)

Parameters

Name Type Default Description
Input value inPolygon const Path&
Output value outElongation float&

Description

Elongation is a measure of how long the polygon is in relation to its width. The perfect circle has the minimal elongation equal to 1.0, while the upper bound doesn't exist. The operation internally approximates the polygon with an ellipse, and then computes the result as: Where L denotes the longer axis of the approximating ellipse, and S denotes the shorter one.

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

Elongation of the sample polygon equals to 3.283.

Elongation of the sample polygon equals to 1.001.

Errors

List of possible exceptions:

Error type Description
DomainError Degenerate polygon on input in PolygonElongation.
DomainError Open path on input in PolygonElongation.

See Also

  • PolygonCircularity – Computes the area of a polygon divided by the area of a circle having the same feature.
  • RegionElongation – Computes the elongation factor of a region ( perfect circle has minimal elongation equal 1.0 ).