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ShapeCircularity
Computes the area of a shape divided by the area of a circle having the same feature.
Syntax
void avl::ShapeCircularity ( const avl::Path& inShape, const avl::CircularityMeasure::Type inCircularityMeasure, float& outCircularity )
Parameters
Name | Type | Default | Description | |
---|---|---|---|---|
inShape | const Path& | |||
inCircularityMeasure | const CircularityMeasure::Type | RadiusPreserving | ||
outCircularity | float& |
Description
Circularity is a measure of similarity of a shape to the perfect circle. Circular shapes 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 shape having the same feature as input shape 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 shape (i.e. it has at least one self-intersection), the computation may lead to results that are not intuitive.
Examples
Errors
Error type | Description |
---|---|
DomainError | Open path on input in ShapeCircularity. |
DomainError | Degenerate shape on input in ShapeCircularity. |
DomainError | Not supported circularity measure in ShapeCircularity. |