New "Quaternion" class. Thanks to Julien Anxionnat.
After applying the original patch, the following changes were made:
* Renamed the "static" quaternion instances ("PLUS_" prefix removed).
* Removed some (syntactic sugar) methods; removed or modified corresponding
  unit tests.
* Made the redundant accessors call the "canonic" ones.
* Removed the default tolerance and added an explicit tolerance parameter
  in methods that depend on equality testing.
* When a "ZeroException" is thrown, the actual value of the norm is provided
  in the detailed message (as the implementation actually does not use a
  strict comparison with 0).
* Added "equals(Object)" and "hashCode" methods.
* Javadoc and formatting. Added license header.
* Removed "toString" documentation (as this representation should not be
  binding). Changed the representation to not use a comma.
* Renamed "scalarMultiply" to "multiply".
* More stringent tolerance used in the unit tests assertions, whenever
  possible.
* Added unit tests.



git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1388099 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Gilles Sadowski 2012-09-20 16:21:46 +00:00
parent 600f00ba58
commit 7a74137904
6 changed files with 876 additions and 1 deletions

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@ -52,6 +52,9 @@ If the output is not quite correct, check for invisible trailing spaces!
<body>
<release version="3.1" date="TBD" description="
">
<action dev="erans" type="add" issue="MATH-863" due-to="Julien Anxionnat">
New "Quaternion" class (package "o.a.c.m.complex").
</action>
<action dev="erans" type="add" issue="MATH-866" due-to="Yannick Tanguy">
Added method to test for floating-point numbers equality with a
relative tolerance (class "o.a.c.m.util.Precision").

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@ -0,0 +1,465 @@
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.math3.complex;
import java.io.Serializable;
import org.apache.commons.math3.util.FastMath;
import org.apache.commons.math3.util.MathUtils;
import org.apache.commons.math3.util.Precision;
import org.apache.commons.math3.exception.DimensionMismatchException;
import org.apache.commons.math3.exception.ZeroException;
import org.apache.commons.math3.exception.util.LocalizedFormats;
/**
* This class implements <a href="http://mathworld.wolfram.com/Quaternion.html">
* quaternions</a> (Hamilton's hypercomplex numbers).
* <br/>
* Instance of this class are guaranteed to be immutable.
*
* @since 3.1
* @version $Id$
*/
public final class Quaternion implements Serializable {
/** Identity quaternion. */
public static final Quaternion IDENTITY = new Quaternion(1, 0, 0, 0);
/** Zero quaternion. */
public static final Quaternion ZERO = new Quaternion(0, 0, 0, 0);
/** i */
public static final Quaternion I = new Quaternion(0, 1, 0, 0);
/** j */
public static final Quaternion J = new Quaternion(0, 0, 1, 0);
/** k */
public static final Quaternion K = new Quaternion(0, 0, 0, 1);
/** Serializable version identifier. */
private static final long serialVersionUID = 20092012L;
/** First component (scalar part). */
private final double q0;
/** Second component (first vector part). */
private final double q1;
/** Third component (second vector part). */
private final double q2;
/** Fourth component (third vector part). */
private final double q3;
/**
* Builds a quaternion from its components.
*
* @param a Scalar component.
* @param b First vector component.
* @param c Second vector component.
* @param d Third vector component.
*/
public Quaternion(final double a,
final double b,
final double c,
final double d) {
this.q0 = a;
this.q1 = b;
this.q2 = c;
this.q3 = d;
}
/**
* Builds a quaternion from scalar and vector parts.
*
* @param scalar Scalar part of the quaternion.
* @param v Components of the vector part of the quaternion.
*
* @throws DimensionMismatchException if the array length is not 3.
*/
public Quaternion(final double scalar,
final double[] v)
throws DimensionMismatchException {
if (v.length != 3) {
throw new DimensionMismatchException(v.length, 3);
}
this.q0 = 0;
this.q1 = v[0];
this.q2 = v[1];
this.q3 = v[2];
}
/**
* Builds a pure quaternion from a vector (assuming that the scalar
* part is zero.
*
* @param v Components of the vector part of the pure quaternion.
*/
public Quaternion(final double[] v) {
this(0, v);
}
/**
* Returns the conjugate quaternion of the instance.
*
* @return the conjugate quaternion
*/
public Quaternion getConjugate() {
return new Quaternion(q0, -q1, -q2, -q3);
}
/**
* Returns the Hamilton product of two quaternions.
*
* @param q1 First quaternion.
* @param q2 Second quaternion.
* @return the product {@code q1} and {@code q2}, in that order.
*/
public static Quaternion product(final Quaternion q1, final Quaternion q2) {
// Components of the first quaternion.
final double q1a = q1.getQ0();
final double q1b = q1.getQ1();
final double q1c = q1.getQ2();
final double q1d = q1.getQ3();
// Components of the second quaternion.
final double q2a = q2.getQ0();
final double q2b = q2.getQ1();
final double q2c = q2.getQ2();
final double q2d = q2.getQ3();
// Components of the product.
final double w = q1a * q2a - q1b * q2b - q1c * q2c - q1d * q2d;
final double x = q1a * q2b + q1b * q2a + q1c * q2d - q1d * q2c;
final double y = q1a * q2c - q1b * q2d + q1c * q2a + q1d * q2b;
final double z = q1a * q2d + q1b * q2c - q1c * q2b + q1d * q2a;
return new Quaternion(w, x, y, z);
}
/**
* Returns the Hamilton product of the instance by a quaternion.
*
* @param q Quaternion.
* @return the product of this instance with {@code q}, in that order.
*/
public Quaternion multiply(final Quaternion q) {
return product(this, q);
}
/**
* Computes the sum of two quaternions.
*
* @param q1 Quaternion.
* @param q2 Quaternion.
* @return the sum of {@code q1} and {@code q2}.
*/
public static Quaternion add(final Quaternion q1,
final Quaternion q2) {
return new Quaternion(q1.getQ0() + q2.getQ0(),
q1.getQ1() + q2.getQ1(),
q1.getQ2() + q2.getQ2(),
q1.getQ3() + q2.getQ3());
}
/**
* Computes the sum of the instance and another quaternion.
*
* @param q Quaternion.
* @return the sum of this instance and {@code q}
*/
public Quaternion add(final Quaternion q) {
return add(this, q);
}
/**
* Subtracts two quaternions.
*
* @param q1 First Quaternion.
* @param q2 Second quaternion.
* @return the difference between {@code q1} and {@code q2}.
*/
public static Quaternion subtract(final Quaternion q1,
final Quaternion q2) {
return new Quaternion(q1.getQ0() - q2.getQ0(),
q1.getQ1() - q2.getQ1(),
q1.getQ2() - q2.getQ2(),
q1.getQ3() - q2.getQ3());
}
/**
* Subtracts a quaternion from the instance.
*
* @param q Quaternion.
* @return the difference between this instance and {@code q}.
*/
public Quaternion subtract(final Quaternion q) {
return subtract(this, q);
}
/**
* Computes the dot-product of two quaternions.
*
* @param q1 Quaternion.
* @param q2 Quaternion.
* @return the dot product of {@code q1} and {@code q2}.
*/
public static double dotProduct(final Quaternion q1,
final Quaternion q2) {
return q1.getQ0() * q2.getQ0() +
q1.getQ1() * q2.getQ1() +
q1.getQ2() * q2.getQ2() +
q1.getQ3() * q2.getQ3();
}
/**
* Compute the dot-product of the instance by a quaternion.
*
* @param q Quaternion.
* @return the dot product of this instance and {@code q}.
*/
public double dotProduct(final Quaternion q) {
return dotProduct(q);
}
/**
* Computes the norm of the quaternion.
*
* @return the norm.
*/
public double getNorm() {
return FastMath.sqrt(q0 * q0 +
q1 * q1 +
q2 * q2 +
q3 * q3);
}
/**
* Computes the normalized quaternion (the versor of the instance).
* The norm of the quaternion must not be zero.
*
* @return a normalized quaternion.
* @throws ZeroException if the norm of the quaternion is zero.
*/
public Quaternion normalize() {
final double norm = getNorm();
if (norm < Precision.SAFE_MIN) {
throw new ZeroException(LocalizedFormats.NORM, norm);
}
return new Quaternion(q0 / norm,
q1 / norm,
q2 / norm,
q3 / norm);
}
/**
* {@inheritDoc}
*/
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (other instanceof Quaternion) {
final Quaternion q = (Quaternion) other;
return q0 == q.getQ0() &&
q1 == q.getQ1() &&
q2 == q.getQ2() &&
q3 == q.getQ3();
}
return false;
}
/**
* {@inheritDoc}
*/
@Override
public int hashCode() {
// "Effective Java" (second edition, p. 47).
int result = 17;
for (double comp : new double[] { q0, q1, q2, q3 }) {
final int c = MathUtils.hash(comp);
result = 31 * result + c;
}
return result;
}
/**
* Checks whether this instance is equal to another quaternion
* within a given tolerance.
*
* @param q Quaternion with which to compare the current quaternion.
* @param eps Tolerance.
* @return {@code true} if the each of the components are equal
* within the allowed absolute error.
*/
public boolean equals(final Quaternion q,
final double eps) {
return Precision.equals(q0, q.getQ0(), eps) &&
Precision.equals(q1, q.getQ1(), eps) &&
Precision.equals(q2, q.getQ2(), eps) &&
Precision.equals(q3, q.getQ3(), eps);
}
/**
* Checks whether the instance is a unit quaternion within a given
* tolerance.
*
* @param eps Tolerance (absolute error).
* @return {@code true} if the norm is 1 within the given tolerance,
* {@code false} otherwise
*/
public boolean isUnitQuaternion(double eps) {
return Precision.equals(getNorm(), 1d, eps);
}
/**
* Checks whether the instance is a pure quaternion within a given
* tolerance.
*
* @param eps Tolerance (absolute error).
* @return {@code true} if the scalar part of the quaternion is zero.
*/
public boolean isPureQuaternion(double eps) {
return FastMath.abs(getQ0()) <= eps;
}
/**
* Returns the polar form of the quaternion.
*
* @return the unit quaternion with positive scalar part.
*/
public Quaternion getPositivePolarForm() {
if (getQ0() < 0) {
final Quaternion unitQ = normalize();
// The quaternion of rotation (normalized quaternion) q and -q
// are equivalent (i.e. represent the same rotation).
return new Quaternion(-unitQ.getQ0(),
-unitQ.getQ1(),
-unitQ.getQ2(),
-unitQ.getQ3());
} else {
return this.normalize();
}
}
/**
* Returns the inverse of this instance.
* The norm of the quaternion must not be zero.
*
* @return the inverse.
* @throws ZeroException if the norm (squared) of the quaternion is zero.
*/
public Quaternion getInverse() {
final double squareNorm = q0 * q0 + q1 * q1 + q2 * q2 + q3 * q3;
if (squareNorm < Precision.SAFE_MIN) {
throw new ZeroException(LocalizedFormats.NORM, squareNorm);
}
return new Quaternion(q0 / squareNorm,
-q1 / squareNorm,
-q2 / squareNorm,
-q3 / squareNorm);
}
/**
* Gets the first component of the quaternion (scalar part).
*
* @return the scalar part.
*/
public double getQ0() {
return q0;
}
/**
* Gets the second component of the quaternion (first component
* of the vector part).
*
* @return the first component of the vector part.
*/
public double getQ1() {
return q1;
}
/**
* Gets the third component of the quaternion (second component
* of the vector part).
*
* @return the second component of the vector part.
*/
public double getQ2() {
return q2;
}
/**
* Gets the fourth component of the quaternion (third component
* of the vector part).
*
* @return the third component of the vector part.
*/
public double getQ3() {
return q3;
}
/**
* Gets the scalar part of the quaternion.
*
* @return the scalar part.
* @see #getQ0()
*/
public double getScalarPart() {
return getQ0();
}
/**
* Gets the three components of the vector part of the quaternion.
*
* @return the vector part.
* @see #getQ1()
* @see #getQ2()
* @see #getQ3()
*/
public double[] getVectorPart() {
return new double[] { getQ1(), getQ2(), getQ3() };
}
/**
* Multiplies the instance by a scalar.
*
* @param alpha Scalar factor.
* @return a scaled quaternion.
*/
public Quaternion multiply(final double alpha) {
return new Quaternion(alpha * q0,
alpha * q1,
alpha * q2,
alpha * q3);
}
/**
* {@inheritDoc}
*/
@Override
public String toString() {
final String sp = " ";
final StringBuilder s = new StringBuilder();
s.append("[")
.append(q0).append(sp)
.append(q1).append(sp)
.append(q2).append(sp)
.append(q3)
.append("]");
return s.toString();
}
}

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@ -182,6 +182,7 @@ public enum LocalizedFormats implements Localizable {
NON_REAL_FINITE_ORDINATE("all ordinatae must be finite real numbers, but {0}-th is {1}"),
NON_REAL_FINITE_WEIGHT("all weights must be finite real numbers, but {0}-th is {1}"),
NON_SQUARE_MATRIX("non square ({0}x{1}) matrix"),
NORM("Norm ({0})"), /* keep */
NORMALIZE_INFINITE("Cannot normalize to an infinite value"),
NORMALIZE_NAN("Cannot normalize to NaN"),
NOT_ADDITION_COMPATIBLE_MATRICES("{0}x{1} and {2}x{3} matrices are not addition compatible"),

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@ -153,6 +153,7 @@ NON_REAL_FINITE_ABSCISSA = toutes les abscisses doivent \u00eatre des nombres r\
NON_REAL_FINITE_ORDINATE = toutes les ordonn\u00e9es doivent \u00eatre des nombres r\u00e9els finis, mais l''ordonn\u00e9e {0} vaut {1}
NON_REAL_FINITE_WEIGHT = tous les poids doivent \u00eatre des nombres r\u00e9els finis, mais le poids {0} vaut {1}
NON_SQUARE_MATRIX = matrice non carr\u00e9e ({0}x{1})
NORM = norme ({0})
NORMALIZE_INFINITE = impossible de normaliser vers une valeur infinie
NORMALIZE_NAN = impossible de normaliser vers NaN
NOT_ADDITION_COMPATIBLE_MATRICES = les dimensions {0}x{1} et {2}x{3} sont incompatibles pour l''addition matricielle

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@ -0,0 +1,405 @@
package org.apache.commons.math3.complex;
import java.util.Random;
import org.apache.commons.math3.complex.Quaternion;
import org.apache.commons.math3.exception.DimensionMismatchException;
import org.apache.commons.math3.exception.ZeroException;
import org.apache.commons.math3.geometry.euclidean.threed.Rotation;
import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;
import org.apache.commons.math3.util.Precision;
import org.apache.commons.math3.util.FastMath;
import org.junit.Test;
import org.junit.Assert;
public class QuaternionTest {
/** Epsilon for double comparison. */
private static final double EPS = Math.ulp(1d);
/** Epsilon for double comparison. */
private static final double COMPARISON_EPS = 1e-14;
@Test
public final void testAccessors1() {
final double q0 = 2;
final double q1 = 5.4;
final double q2 = 17;
final double q3 = 0.0005;
final Quaternion q = new Quaternion(q0, q1, q2, q3);
Assert.assertEquals(q0, q.getQ0(), 0);
Assert.assertEquals(q1, q.getQ1(), 0);
Assert.assertEquals(q2, q.getQ2(), 0);
Assert.assertEquals(q3, q.getQ3(), 0);
}
@Test
public final void testAccessors2() {
final double q0 = 2;
final double q1 = 5.4;
final double q2 = 17;
final double q3 = 0.0005;
final Quaternion q = new Quaternion(q0, q1, q2, q3);
final double sP = q.getScalarPart();
final double[] vP = q.getVectorPart();
Assert.assertEquals(q0, sP, 0);
Assert.assertEquals(q1, vP[0], 0);
Assert.assertEquals(q2, vP[1], 0);
Assert.assertEquals(q3, vP[2], 0);
}
@Test(expected=DimensionMismatchException.class)
public void testWrongDimension() {
new Quaternion(new double[] { 1, 2 });
}
@Test
public final void testConjugate() {
final double q0 = 2;
final double q1 = 5.4;
final double q2 = 17;
final double q3 = 0.0005;
final Quaternion q = new Quaternion(q0, q1, q2, q3);
final Quaternion qConjugate = q.getConjugate();
Assert.assertEquals(q0, qConjugate.getQ0(), 0);
Assert.assertEquals(-q1, qConjugate.getQ1(), 0);
Assert.assertEquals(-q2, qConjugate.getQ2(), 0);
Assert.assertEquals(-q3, qConjugate.getQ3(), 0);
}
@Test
public final void testProductQuaternionQuaternion() {
// Case : analytic test case
final Quaternion qA = new Quaternion(1, 0.5, -3, 4);
final Quaternion qB = new Quaternion(6, 2, 1, -9);
final Quaternion qResult = Quaternion.product(qA, qB);
Assert.assertEquals(44, qResult.getQ0(), EPS);
Assert.assertEquals(28, qResult.getQ1(), EPS);
Assert.assertEquals(-4.5, qResult.getQ2(), EPS);
Assert.assertEquals(21.5, qResult.getQ3(), EPS);
// comparison with the result given by the formula :
// qResult = (scalarA * scalarB - vectorA . vectorB) + (scalarA * vectorB + scalarB * vectorA + vectorA ^
// vectorB)
final Vector3D vectorA = new Vector3D(qA.getVectorPart());
final Vector3D vectorB = new Vector3D(qB.getVectorPart());
final Vector3D vectorResult = new Vector3D(qResult.getVectorPart());
final double scalarPartRef = qA.getScalarPart() * qB.getScalarPart() - Vector3D.dotProduct(vectorA, vectorB);
Assert.assertEquals(scalarPartRef, qResult.getScalarPart(), EPS);
final Vector3D vectorPartRef = ((vectorA.scalarMultiply(qB.getScalarPart())).add(vectorB.scalarMultiply(qA
.getScalarPart()))).add(Vector3D.crossProduct(vectorA, vectorB));
final double norm = (vectorResult.subtract(vectorPartRef)).getNorm();
Assert.assertEquals(0, norm, EPS);
// Conjugate of the product of two quaternions and product of their conjugates :
// Conj(qA * qB) = Conj(qB) * Conj(qA)
final Quaternion conjugateOfProduct = Quaternion.product(qB.getConjugate(), qA.getConjugate());
final Quaternion productOfConjugate = (Quaternion.product(qA, qB)).getConjugate();
Assert.assertEquals(conjugateOfProduct.getQ0(), productOfConjugate.getQ0(), EPS);
Assert.assertEquals(conjugateOfProduct.getQ1(), productOfConjugate.getQ1(), EPS);
Assert.assertEquals(conjugateOfProduct.getQ2(), productOfConjugate.getQ2(), EPS);
Assert.assertEquals(conjugateOfProduct.getQ3(), productOfConjugate.getQ3(), EPS);
}
@Test
public final void testProductQuaternionVector() {
// Case : Product between a vector and a quaternion : QxV
final Quaternion quaternion = new Quaternion(4, 7, -1, 2);
final double[] vector = {2.0, 1.0, 3.0};
final Quaternion qResultQxV = Quaternion.product(quaternion, new Quaternion(vector));
Assert.assertEquals(-19, qResultQxV.getQ0(), EPS);
Assert.assertEquals(3, qResultQxV.getQ1(), EPS);
Assert.assertEquals(-13, qResultQxV.getQ2(), EPS);
Assert.assertEquals(21, qResultQxV.getQ3(), EPS);
// comparison with the result given by the formula :
// qResult = (- vectorQ . vector) + (scalarQ * vector + vectorQ ^ vector)
final double[] vectorQ = quaternion.getVectorPart();
final double[] vectorResultQxV = qResultQxV.getVectorPart();
final double scalarPartRefQxV = -Vector3D.dotProduct(new Vector3D(vectorQ), new Vector3D(vector));
Assert.assertEquals(scalarPartRefQxV, qResultQxV.getScalarPart(), EPS);
final Vector3D vectorPartRefQxV = (new Vector3D(vector).scalarMultiply(quaternion.getScalarPart())).add(Vector3D
.crossProduct(new Vector3D(vectorQ), new Vector3D(vector)));
final double normQxV = (new Vector3D(vectorResultQxV).subtract(vectorPartRefQxV)).getNorm();
Assert.assertEquals(0, normQxV, EPS);
// Case : Product between a vector and a quaternion : VxQ
final Quaternion qResultVxQ = Quaternion.product(new Quaternion(vector), quaternion);
Assert.assertEquals(-19, qResultVxQ.getQ0(), EPS);
Assert.assertEquals(13, qResultVxQ.getQ1(), EPS);
Assert.assertEquals(21, qResultVxQ.getQ2(), EPS);
Assert.assertEquals(3, qResultVxQ.getQ3(), EPS);
final double[] vectorResultVxQ = qResultVxQ.getVectorPart();
// comparison with the result given by the formula :
// qResult = (- vector . vectorQ) + (scalarQ * vector + vector ^ vectorQ)
final double scalarPartRefVxQ = -Vector3D.dotProduct(new Vector3D(vectorQ), new Vector3D(vector));
Assert.assertEquals(scalarPartRefVxQ, qResultVxQ.getScalarPart(), EPS);
final Vector3D vectorPartRefVxQ = (new Vector3D(vector).scalarMultiply(quaternion.getScalarPart())).add(Vector3D
.crossProduct(new Vector3D(vector), new Vector3D(vectorQ)));
final double normVxQ = (new Vector3D(vectorResultVxQ).subtract(vectorPartRefVxQ)).getNorm();
Assert.assertEquals(0, normVxQ, EPS);
}
@Test
public final void testDotProductQuaternionQuaternion() {
// expected output
final double expected = -6.;
// inputs
final Quaternion q1 = new Quaternion(1, 2, 2, 1);
final Quaternion q2 = new Quaternion(3, -2, -1, -3);
final double actual = Quaternion.dotProduct(q1, q2);
Assert.assertEquals(expected, actual, EPS);
}
@Test
public final void testScalarMultiplyDouble() {
// expected outputs
final double w = 1.6;
final double x = -4.8;
final double y = 11.20;
final double z = 2.56;
// inputs
final Quaternion q1 = new Quaternion(0.5, -1.5, 3.5, 0.8);
final double a = 3.2;
final Quaternion q = q1.multiply(a);
Assert.assertEquals(w, q.getQ0(), COMPARISON_EPS);
Assert.assertEquals(x, q.getQ1(), COMPARISON_EPS);
Assert.assertEquals(y, q.getQ2(), COMPARISON_EPS);
Assert.assertEquals(z, q.getQ3(), COMPARISON_EPS);
}
@Test
public final void testAddQuaternionQuaternion() {
// expected outputs
final double w = 4;
final double x = -1;
final double y = 2;
final double z = -4;
// inputs
final Quaternion q1 = new Quaternion(1., 2., -2., -1.);
final Quaternion q2 = new Quaternion(3., -3., 4., -3.);
final Quaternion q = Quaternion.add(q1, q2);
Assert.assertEquals(w, q.getQ0(), EPS);
Assert.assertEquals(x, q.getQ1(), EPS);
Assert.assertEquals(y, q.getQ2(), EPS);
Assert.assertEquals(z, q.getQ3(), EPS);
}
@Test
public final void testSubtractQuaternionQuaternion() {
// expected outputs
final double w = -2.;
final double x = 5.;
final double y = -6.;
final double z = 2.;
// inputs
final Quaternion q1 = new Quaternion(1., 2., -2., -1.);
final Quaternion q2 = new Quaternion(3., -3., 4., -3.);
final Quaternion q = Quaternion.subtract(q1, q2);
Assert.assertEquals(w, q.getQ0(), EPS);
Assert.assertEquals(x, q.getQ1(), EPS);
Assert.assertEquals(y, q.getQ2(), EPS);
Assert.assertEquals(z, q.getQ3(), EPS);
}
@Test
public final void testNorm() {
final double q0 = 2;
final double q1 = 1;
final double q2 = -4;
final double q3 = 3;
final Quaternion q = new Quaternion(q0, q1, q2, q3);
final double norm = q.getNorm();
Assert.assertEquals(Math.sqrt(30), norm, 0);
final double normSquareRef = Quaternion.product(q, q.getConjugate()).getScalarPart();
Assert.assertEquals(Math.sqrt(normSquareRef), norm, 0);
}
@Test
public final void testNormalize() {
final Quaternion q = new Quaternion(2, 1, -4, -2);
final Quaternion versor = q.normalize();
Assert.assertEquals(2.0 / 5.0, versor.getQ0(), 0);
Assert.assertEquals(1.0 / 5.0, versor.getQ1(), 0);
Assert.assertEquals(-4.0 / 5.0, versor.getQ2(), 0);
Assert.assertEquals(-2.0 / 5.0, versor.getQ3(), 0);
Assert.assertEquals(1, versor.getNorm(), 0);
}
@Test(expected=ZeroException.class)
public final void testNormalizeFail() {
final Quaternion zeroQ = new Quaternion(0, 0, 0, 0);
zeroQ.normalize();
}
@Test
public final void testObjectEquals() {
final double one = 1;
final Quaternion q1 = new Quaternion(one, one, one, one);
Assert.assertTrue(q1.equals(q1));
final Quaternion q2 = new Quaternion(one, one, one, one);
Assert.assertTrue(q2.equals(q1));
final Quaternion q3 = new Quaternion(one, FastMath.nextUp(one), one, one);
Assert.assertFalse(q3.equals(q1));
}
@Test
public final void testQuaternionEquals() {
final double inc = 1e-5;
final Quaternion q1 = new Quaternion(2, 1, -4, -2);
final Quaternion q2 = new Quaternion(q1.getQ0() + inc, q1.getQ1(), q1.getQ2(), q1.getQ3());
final Quaternion q3 = new Quaternion(q1.getQ0(), q1.getQ1() + inc, q1.getQ2(), q1.getQ3());
final Quaternion q4 = new Quaternion(q1.getQ0(), q1.getQ1(), q1.getQ2() + inc, q1.getQ3());
final Quaternion q5 = new Quaternion(q1.getQ0(), q1.getQ1(), q1.getQ2(), q1.getQ3() + inc);
Assert.assertFalse(q1.equals(q2, 0.9 * inc));
Assert.assertFalse(q1.equals(q3, 0.9 * inc));
Assert.assertFalse(q1.equals(q4, 0.9 * inc));
Assert.assertFalse(q1.equals(q5, 0.9 * inc));
Assert.assertTrue(q1.equals(q2, 1.1 * inc));
Assert.assertTrue(q1.equals(q3, 1.1 * inc));
Assert.assertTrue(q1.equals(q4, 1.1 * inc));
Assert.assertTrue(q1.equals(q5, 1.1 * inc));
}
@Test
public final void testQuaternionEquals2() {
final Quaternion q1 = new Quaternion(1, 4, 2, 3);
final double gap = 1e-5;
final Quaternion q2 = new Quaternion(1 + gap, 4 + gap, 2 + gap, 3 + gap);
Assert.assertTrue(q1.equals(q2, 10 * gap));
Assert.assertFalse(q1.equals(q2, gap));
Assert.assertFalse(q1.equals(q2, gap / 10));
}
@Test
public final void testIsUnitQuaternion() {
final Random r = new Random(48);
final int numberOfTrials = 1000;
for (int i = 0; i < numberOfTrials; i++) {
final Quaternion q1 = new Quaternion(r.nextDouble(), r.nextDouble(), r.nextDouble(), r.nextDouble());
final Quaternion q2 = q1.normalize();
Assert.assertTrue(q2.isUnitQuaternion(COMPARISON_EPS));
}
final Quaternion q = new Quaternion(1, 1, 1, 1);
Assert.assertFalse(q.isUnitQuaternion(COMPARISON_EPS));
}
@Test
public final void testIsPureQuaternion() {
final Quaternion q1 = new Quaternion(0, 5, 4, 8);
Assert.assertTrue(q1.isPureQuaternion(EPS));
final Quaternion q2 = new Quaternion(0 - EPS, 5, 4, 8);
Assert.assertTrue(q2.isPureQuaternion(EPS));
final Quaternion q3 = new Quaternion(0 - 1.1 * EPS, 5, 4, 8);
Assert.assertFalse(q3.isPureQuaternion(EPS));
final Random r = new Random(48);
final double[] v = {r.nextDouble(), r.nextDouble(), r.nextDouble()};
final Quaternion q4 = new Quaternion(v);
Assert.assertTrue(q4.isPureQuaternion(0));
final Quaternion q5 = new Quaternion(0, v);
Assert.assertTrue(q5.isPureQuaternion(0));
}
@Test
public final void testPolarForm() {
final Random r = new Random(48);
final int numberOfTrials = 1000;
for (int i = 0; i < numberOfTrials; i++) {
final Quaternion q = new Quaternion(2 * (r.nextDouble() - 0.5), 2 * (r.nextDouble() - 0.5),
2 * (r.nextDouble() - 0.5), 2 * (r.nextDouble() - 0.5));
final Quaternion qP = q.getPositivePolarForm();
Assert.assertTrue(qP.isUnitQuaternion(COMPARISON_EPS));
Assert.assertTrue(qP.getQ0() >= 0);
final Rotation rot = new Rotation(q.getQ0(), q.getQ1(), q.getQ2(), q.getQ3(), true);
final Rotation rotP = new Rotation(qP.getQ0(), qP.getQ1(), qP.getQ2(), qP.getQ3(), true);
Assert.assertEquals(rot.getAngle(), rotP.getAngle(), COMPARISON_EPS);
Assert.assertEquals(rot.getAxis().getX(), rot.getAxis().getX(), COMPARISON_EPS);
Assert.assertEquals(rot.getAxis().getY(), rot.getAxis().getY(), COMPARISON_EPS);
Assert.assertEquals(rot.getAxis().getZ(), rot.getAxis().getZ(), COMPARISON_EPS);
}
}
@Test
public final void testGetInverse() {
final Quaternion q = new Quaternion(1.5, 4, 2, -2.5);
final Quaternion inverseQ = q.getInverse();
Assert.assertEquals(1.5 / 28.5, inverseQ.getQ0(), 0);
Assert.assertEquals(-4.0 / 28.5, inverseQ.getQ1(), 0);
Assert.assertEquals(-2.0 / 28.5, inverseQ.getQ2(), 0);
Assert.assertEquals(2.5 / 28.5, inverseQ.getQ3(), 0);
final Quaternion product = Quaternion.product(inverseQ, q);
Assert.assertEquals(1, product.getQ0(), EPS);
Assert.assertEquals(0, product.getQ1(), EPS);
Assert.assertEquals(0, product.getQ2(), EPS);
Assert.assertEquals(0, product.getQ3(), EPS);
final Quaternion qNul = new Quaternion(0, 0, 0, 0);
try {
final Quaternion inverseQNul = qNul.getInverse();
Assert.fail("expecting ZeroException but got : " + inverseQNul);
} catch (ZeroException ex) {
// expected
}
}
@Test
public final void testToString() {
final Quaternion q = new Quaternion(1, 2, 3, 4);
Assert.assertTrue(q.toString().equals("[1.0 2.0 3.0 4.0]"));
}
}

View File

@ -36,7 +36,7 @@ public class LocalizedFormatsTest {
@Test
public void testMessageNumber() {
Assert.assertEquals(310, LocalizedFormats.values().length);
Assert.assertEquals(311, LocalizedFormats.values().length);
}
@Test