us.ihmc.euclid.tuple4D.interfaces

Interface Vector4DReadOnly

All Superinterfaces:

Tuple4DReadOnly

All Known Subinterfaces:

Vector4DBasics

All Known Implementing Classes:

Vector4D, Vector4D32

public interface Vector4DReadOnly
extends Tuple4DReadOnly

Read-only interface for a 4 dimensional vector representing a generic quaternion.

When describing a 4D tuple, its 4 components are often gathered in two groups: the scalar part s and the vector part (x, y, z).

Note on the difference between applying a 3D transform on a quaternion and a 4D vector:

• When transformed by a homogeneous transformation matrix, a quaternion is only pre-multiplied by the rotation part of the transform, resulting in concatenating the orientations of the transform and the quaternion.
• When transformed by a homogeneous transformation matrix, a 4D vector scalar part s remains unchanged. The vector part (x, y, z) is scaled and rotated, and translated by s times the translation part of the transform. Note that for s = 0, a 4D vector behaves as a 3D vector, and for s = 1 it behaves as a 3D point.

Method Summary

Modifier and Type	Method and Description
default boolean	geometricallyEquals(Vector4DReadOnly other, double epsilon) Tests if this and other represent the same vector 4D to an epsilon.

Methods inherited from interface us.ihmc.euclid.tuple4D.interfaces.Tuple4DReadOnly

containsNaN, dot, epsilonEquals, equals, get, get, get, get, get, get, get, getElement, getElement32, getS, getS32, getX, getX32, getY, getY32, getZ, getZ32, norm, normSquared

Method Detail

geometricallyEquals

default boolean geometricallyEquals(Vector4DReadOnly other,
                                    double epsilon)

Tests if this and other represent the same vector 4D to an epsilon.

Two vectors are considered geometrically equal if the length of their difference is less than or equal to epsilon.

Note that this.geometricallyEquals(other, epsilon) == true does not necessarily imply this.epsilonEquals(other, epsilon) and vice versa.

Parameters:

other - the other vector 4D to compare against this. Not modified.

epsilon - the maximum length of the difference vector can be for the two vectors to be considered equal.

Returns:

true if the two vectors represent the same geometry, false otherwise.