org.apache.commons.geometry.euclidean.twod

Class Vector2D.Unit

java.lang.Object

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

org.apache.commons.geometry.euclidean.MultiDimensionalEuclideanVector<Vector2D>

org.apache.commons.geometry.euclidean.twod.Vector2D

org.apache.commons.geometry.euclidean.twod.Vector2D.Unit

All Implemented Interfaces:

Point<Vector2D>, Spatial, Vector<Vector2D>

Enclosing class:

Vector2D

public static final class Vector2D.Unit
extends Vector2D

Represents unit vectors. This allows optimizations for certain operations.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.commons.geometry.euclidean.twod.Vector2D

Vector2D.Sum, Vector2D.Unit

Field Summary

Fields

Modifier and Type	Field and Description
static Vector2D.Unit	MINUS_X Negation of unit vector (coordinates: -1, 0).
static Vector2D.Unit	MINUS_Y Negation of unit vector (coordinates: 0, -1).
static Vector2D.Unit	PLUS_X Unit vector (coordinates: 1, 0).
static Vector2D.Unit	PLUS_Y Unit vector (coordinates: 0, 1).

Fields inherited from class org.apache.commons.geometry.euclidean.twod.Vector2D

COORDINATE_ASCENDING_ORDER, NaN, NEGATIVE_INFINITY, POSITIVE_INFINITY, ZERO

Method Summary

Modifier and Type	Method and Description
static Vector2D.Unit	from(double x, double y) Create a normalized vector.
static Vector2D.Unit	from(Vector2D v) Create a normalized vector.
Vector2D.Unit	negate()
double	norm()
Vector2D.Unit	normalize()
Vector2D.Unit	normalizeOrNull()
double	normSq()
Vector2D.Unit	orthogonal() Get a unit vector orthogonal to the instance.
Vector2D	withNorm(double mag)

Methods inherited from class org.apache.commons.geometry.euclidean.twod.Vector2D

add, add, angle, centroid, centroid, directionTo, distance, distanceSq, dot, eq, equals, getDimension, getX, getY, getZero, hashCode, isFinite, isInfinite, isNaN, lerp, max, max, min, min, multiply, of, of, orthogonal, parse, project, reject, signedArea, subtract, subtract, toArray, toString, transform, vectorTo

Methods inherited from class org.apache.commons.geometry.euclidean.EuclideanVector

getCheckedNorm, isZero

Methods inherited from class java.lang.Object

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

Field Detail

PLUS_X

public static final Vector2D.Unit PLUS_X

Unit vector (coordinates: 1, 0).

MINUS_X

public static final Vector2D.Unit MINUS_X

Negation of unit vector (coordinates: -1, 0).

PLUS_Y

public static final Vector2D.Unit PLUS_Y

Unit vector (coordinates: 0, 1).

MINUS_Y

public static final Vector2D.Unit MINUS_Y

Negation of unit vector (coordinates: 0, -1).

Method Detail

norm

public double norm()

Specified by:

norm in interface Vector<Vector2D>

Overrides:

norm in class Vector2D

normSq

public double normSq()

Specified by:

normSq in interface Vector<Vector2D>

Overrides:

normSq in class Vector2D

normalize

public Vector2D.Unit normalize()

Specified by:

normalize in interface Vector<Vector2D>

Overrides:

normalize in class Vector2D

normalizeOrNull

public Vector2D.Unit normalizeOrNull()

Specified by:

normalizeOrNull in interface Vector<Vector2D>

Overrides:

normalizeOrNull in class Vector2D

orthogonal

public Vector2D.Unit orthogonal()

Get a unit vector orthogonal to the instance. The returned vector is computed by rotating the current instance pi/2 radians counterclockwise around the origin and normalizing. For example, if this method is called on a vector pointing along the positive x-axis, then a unit vector representing the positive y-axis is returned.

Overrides:

orthogonal in class Vector2D

Returns:

a unit vector orthogonal to the current instance

withNorm

public Vector2D withNorm(double mag)

Specified by:

withNorm in interface Vector<Vector2D>

Overrides:

withNorm in class Vector2D

negate

public Vector2D.Unit negate()

Specified by:

negate in interface Vector<Vector2D>

Overrides:

negate in class Vector2D

from

public static Vector2D.Unit from(double x,
                                 double y)

Create a normalized vector.

Parameters:

x - Vector coordinate.

y - Vector coordinate.

Returns:

a vector whose norm is 1.

Throws:

IllegalArgumentException - if the norm of the given value is zero, NaN, or infinite

from

public static Vector2D.Unit from(Vector2D v)

Create a normalized vector.

Parameters:

v - Vector.

Returns:

a vector whose norm is 1.

Throws:

IllegalArgumentException - if the norm of the given value is zero, NaN, or infinite