Package org.hipparchus.geometry.spherical.oned

Class S1Point

java.lang.Object

org.hipparchus.geometry.spherical.oned.S1Point

All Implemented Interfaces:

Serializable, Point<Sphere1D,S1Point>

public class S1Point
extends Object
implements Point<Sphere1D,S1Point>

This class represents a point on the 1-sphere.

Instances of this class are guaranteed to be immutable.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final S1Point	NaN	A vector with all coordinates set to NaN.

Constructor Summary

Constructors

Constructor	Description
S1Point(double alpha)	Simple constructor.

Method Summary

Modifier and Type	Method	Description
double	distance(S1Point point)	Compute the distance between the instance and another point.
static double	distance(S1Point p1, S1Point p2)	Compute the distance (angular separation) between two points.
boolean	equals(Object other)	Test for the equality of two points on the 1-sphere.
boolean	equalsIeee754(Object other)	Test for the equality of two points on the 1-sphere.
double	getAlpha()	Get the azimuthal angle $\alpha$.
Space	getSpace()	Get the space to which the point belongs.
Vector2D	getVector()	Get the corresponding normalized vector in the 2D euclidean space.
int	hashCode()	Get a hashCode for the point.
boolean	isNaN()	Returns true if any coordinate of this point is NaN; false otherwise
S1Point	moveTowards(S1Point other, double ratio)	Move towards another point.

Methods inherited from class java.lang.Object

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

Field Details

NaN

public static final S1Point NaN

A vector with all coordinates set to NaN.

Constructor Details

S1Point

public S1Point(double alpha)

Simple constructor. Build a vector from its coordinates

Parameters:

alpha - azimuthal angle $\alpha$

See Also:

• getAlpha()

Method Details

getAlpha

public double getAlpha()

Get the azimuthal angle $\alpha$.

Returns:

azimuthal angle $\alpha$

See Also:

• S1Point(double)

getVector

public Vector2D getVector()

Get the corresponding normalized vector in the 2D euclidean space.

Returns:

normalized vector

getSpace

public Space getSpace()

Get the space to which the point belongs.

Specified by:

getSpace in interface Point<Sphere1D,S1Point>

Returns:

containing space

isNaN

public boolean isNaN()

Returns true if any coordinate of this point is NaN; false otherwise

Specified by:

isNaN in interface Point<Sphere1D,S1Point>

Returns:

true if any coordinate of this point is NaN; false otherwise

distance

public double distance(S1Point point)

Compute the distance between the instance and another point.

Specified by:

distance in interface Point<Sphere1D,S1Point>

Parameters:

point - second point

Returns:

the distance between the instance and p

distance

public static double distance(S1Point p1,
 S1Point p2)

Compute the distance (angular separation) between two points.

Parameters:

p1 - first vector

p2 - second vector

Returns:

the angular separation between p1 and p2

moveTowards

public S1Point moveTowards(S1Point other,
 double ratio)

Move towards another point.

Motion is linear (along space curvature) and based on a ratio where 0.0 stands for not moving at all, 0.5 stands for moving halfway towards other point, and 1.0 stands for moving fully to the other point.

Specified by:

moveTowards in interface Point<Sphere1D,S1Point>

Parameters:

other - other point

ratio - motion ratio,

Returns:

moved point

equals

public boolean equals(Object other)

Test for the equality of two points on the 1-sphere.

If all coordinates of two points are exactly the same, and none are Double.NaN, the two points are considered to be equal.

NaN coordinates are considered to affect globally the point and be equals to each other - i.e, if either (or all) coordinates of the point are equal to Double.NaN, the point is equal to NaN.

Overrides:

equals in class Object

Parameters:

other - Object to test for equality to this

Returns:

true if two points on the 1-sphere objects are equal, false if object is null, not an instance of S1Point, or not equal to this S1Point instance

equalsIeee754

public boolean equalsIeee754(Object other)

Test for the equality of two points on the 1-sphere.

If all coordinates of two points are exactly the same, and none are Double.NaN, the two points are considered to be equal.

In compliance with IEEE754 handling, if any coordinates of any of the two points are NaN, then the points are considered different. This implies that S1Point.NaN.equals(S1Point.NaN) returns false despite the instance is checked against itself.

Parameters:

other - Object to test for equality to this

Returns:

true if two points objects are equal, false if object is null, not an instance of S1Point, or not equal to this S1Point instance

Since:

2.1

hashCode

public int hashCode()

Get a hashCode for the point.

All NaN values have the same hash code.

Overrides:

hashCode in class Object

Returns:

a hash code value for this object