Package org.apache.commons.math3.geometry.euclidean.twod.hull

Class AbstractConvexHullGenerator2D

java.lang.Object

org.apache.commons.math3.geometry.euclidean.twod.hull.AbstractConvexHullGenerator2D

All Implemented Interfaces:

ConvexHullGenerator2D, ConvexHullGenerator<Euclidean2D,Vector2D>

Direct Known Subclasses:

MonotoneChain

abstract class AbstractConvexHullGenerator2D
extends java.lang.Object
implements ConvexHullGenerator2D

Abstract base class for convex hull generators in the two-dimensional euclidean space.

Since:

3.3

Field Summary

Fields

Modifier and Type	Field	Description
private static double	DEFAULT_TOLERANCE	Default value for tolerance.
private boolean	includeCollinearPoints	Indicates if collinear points on the hull shall be present in the output.
private double	tolerance	Tolerance below which points are considered identical.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractConvexHullGenerator2D(boolean includeCollinearPoints)	Simple constructor.
protected	AbstractConvexHullGenerator2D(boolean includeCollinearPoints, double tolerance)	Simple constructor.

Method Summary

Modifier and Type	Method	Description
protected abstract java.util.Collection<Vector2D>	findHullVertices(java.util.Collection<Vector2D> points)	Find the convex hull vertices from the set of input points.
ConvexHull2D	generate(java.util.Collection<Vector2D> points)	Builds the convex hull from the set of input points.
double	getTolerance()	Get the tolerance below which points are considered identical.
boolean	isIncludeCollinearPoints()	Returns if collinear points on the hull will be added as hull vertices.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_TOLERANCE

private static final double DEFAULT_TOLERANCE

Default value for tolerance.

See Also:

Constant Field Values

tolerance

private final double tolerance

Tolerance below which points are considered identical.

includeCollinearPoints

private final boolean includeCollinearPoints

Indicates if collinear points on the hull shall be present in the output. If false, only the extreme points are added to the hull.

Constructor Detail

AbstractConvexHullGenerator2D

protected AbstractConvexHullGenerator2D(boolean includeCollinearPoints)

Simple constructor.

The default tolerance (1e-10) will be used to determine identical points.

Parameters:

includeCollinearPoints - indicates if collinear points on the hull shall be added as hull vertices

AbstractConvexHullGenerator2D

protected AbstractConvexHullGenerator2D(boolean includeCollinearPoints,
                                        double tolerance)

Simple constructor.

Parameters:

includeCollinearPoints - indicates if collinear points on the hull shall be added as hull vertices

tolerance - tolerance below which points are considered identical

Method Detail

getTolerance

public double getTolerance()

Get the tolerance below which points are considered identical.

Returns:

the tolerance below which points are considered identical

isIncludeCollinearPoints

public boolean isIncludeCollinearPoints()

Returns if collinear points on the hull will be added as hull vertices.

Returns:

true if collinear points are added as hull vertices, or false if only extreme points are present.

generate

public ConvexHull2D generate(java.util.Collection<Vector2D> points)
                      throws NullArgumentException,
                             ConvergenceException

Builds the convex hull from the set of input points.

Specified by:

generate in interface ConvexHullGenerator<Euclidean2D,Vector2D>

Specified by:

generate in interface ConvexHullGenerator2D

Parameters:

points - the set of input points

Returns:

the convex hull

Throws:

NullArgumentException - if the input collection is null

ConvergenceException - if generator fails to generate a convex hull for the given set of input points

findHullVertices

protected abstract java.util.Collection<Vector2D> findHullVertices(java.util.Collection<Vector2D> points)

Find the convex hull vertices from the set of input points.

Parameters:

points - the set of input points

Returns:

the convex hull vertices in CCW winding