org.apache.commons.geometry.euclidean

Class AbstractNSphere<V extends EuclideanVector<V>>

java.lang.Object

org.apache.commons.geometry.euclidean.AbstractNSphere<V>

Type Parameters:

V - Vector implementation type

All Implemented Interfaces:

Region<V>, Sized

Direct Known Subclasses:

Circle, Sphere

public abstract class AbstractNSphere<V extends EuclideanVector<V>>
extends Object
implements Region<V>

Abstract base class representing an n-sphere, which is a generalization of the ordinary 3 dimensional sphere to arbitrary dimensions.

See Also:

N-sphere

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractNSphere(V center, double radius, Precision.DoubleEquivalence precision) Construct a new instance from its component parts.

Method Summary

Modifier and Type	Method and Description
RegionLocation	classify(V pt)
boolean	equals(Object obj)
protected <L extends Embedding<V,Vector1D>> V	firstIntersection(L line, ToDoubleBiFunction<L,V> abscissaFn, ToDoubleBiFunction<L,V> distanceFn) Internal method to compute the first intersection between a line and this instance.
V	getCenter() Get the center point of the n-sphere.
V	getCentroid()
Precision.DoubleEquivalence	getPrecision() Get the precision object used to perform floating point comparisons for this instance.
double	getRadius() Get the radius of the n-sphere.
int	hashCode()
protected <L extends Embedding<V,Vector1D>> List<V>	intersections(L line, ToDoubleBiFunction<L,V> abscissaFn, ToDoubleBiFunction<L,V> distanceFn) Internal method to compute the intersections between a line and this instance.
boolean	isEmpty()
boolean	isFull()
protected V	project(V pt, V defaultVector) Project the given point to the boundary of the n-sphere.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.commons.geometry.core.Region

contains, getBoundarySize, project

Methods inherited from interface org.apache.commons.geometry.core.Sized

getSize, isFinite, isInfinite

Constructor Detail

AbstractNSphere

protected AbstractNSphere(V center,
                          double radius,
                          Precision.DoubleEquivalence precision)

Construct a new instance from its component parts.

Parameters:

center - the center point of the n-sphere

radius - the radius of the n-sphere

precision - precision context used to perform floating point comparisons

Throws:

IllegalArgumentException - if center is not finite or radius is not finite or is less than or equal to zero as evaluated by the given precision context

Method Detail

getCenter

public V getCenter()

Get the center point of the n-sphere.

Returns:

the center of the n-sphere

getRadius

public double getRadius()

Get the radius of the n-sphere.

Returns:

the radius of the n-sphere.

getPrecision

public Precision.DoubleEquivalence getPrecision()

Get the precision object used to perform floating point comparisons for this instance.

Returns:

the precision object for this instance

isFull

public boolean isFull()

This method always returns false.

Specified by:

isFull in interface Region<V extends EuclideanVector<V>>

isEmpty

public boolean isEmpty()

This method always returns false.

Specified by:

isEmpty in interface Region<V extends EuclideanVector<V>>

getCentroid

public V getCentroid()

This method is an alias for getCenter().

Specified by:

getCentroid in interface Region<V extends EuclideanVector<V>>

classify

public RegionLocation classify(V pt)

Specified by:

classify in interface Region<V extends EuclideanVector<V>>

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

project

protected V project(V pt,
                    V defaultVector)

Project the given point to the boundary of the n-sphere. If the given point is exactly equal to the n-sphere center, it is projected to the boundary in the direction of defaultVector.

Parameters:

pt - the point to project

defaultVector - the direction to project the point if it lies exactly at the center of the n-sphere

Returns:

the projected point

intersections

protected <L extends Embedding<V,Vector1D>> List<V> intersections(L line,
                                                                  ToDoubleBiFunction<L,V> abscissaFn,
                                                                  ToDoubleBiFunction<L,V> distanceFn)

Internal method to compute the intersections between a line and this instance. The returned list will contain either 0, 1, or 2 points.

• 2 points - The line is a secant line and intersects the n-sphere at two distinct points. The points are ordered such that the first point in the list is the first point encountered when traveling in the direction of the line. (In other words, the points are ordered by increasing abscissa value.)
• 1 point - The line is a tangent line and only intersects the n-sphere at a single point (as evaluated by the n-sphere's precision context).
• 0 points - The line does not intersect the n-sphere.

Type Parameters:

L - Line implementation type

Parameters:

line - line to intersect with the n-sphere

abscissaFn - function used to compute the abscissa value of a point on a line

distanceFn - function used to compute the smallest distance between a point and a line

Returns:

a list of intersection points between the given line and this n-sphere

firstIntersection

protected <L extends Embedding<V,Vector1D>> V firstIntersection(L line,
                                                                ToDoubleBiFunction<L,V> abscissaFn,
                                                                ToDoubleBiFunction<L,V> distanceFn)

Internal method to compute the first intersection between a line and this instance.

Type Parameters:

L - Line implementation type

Parameters:

line - line to intersect with the n-sphere

abscissaFn - function used to compute the abscissa value of a point on a line

distanceFn - function used to compute the smallest distance between a point and a line

Returns:

the first intersection between the given line and this instance or null if no such intersection exists