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Posted to commits@commons.apache.org by ra...@apache.org on 2017/09/16 17:35:03 UTC

[4/8] [math] MATH-1416: Remove Quaternion from commons-math as it have been moved to commons-numbers

MATH-1416: Remove Quaternion from commons-math as it have been moved to commons-numbers

Project: http://git-wip-us.apache.org/repos/asf/commons-math/repo
Commit: http://git-wip-us.apache.org/repos/asf/commons-math/commit/e415b2f4
Tree: http://git-wip-us.apache.org/repos/asf/commons-math/tree/e415b2f4
Diff: http://git-wip-us.apache.org/repos/asf/commons-math/diff/e415b2f4

Branch: refs/heads/feature-MATH-1416
Commit: e415b2f4f3f5f4d103c249009cd313c6be011946
Parents: 63bb89e
Author: Ray DeCampo <ra...@decampo.org>
Authored: Sat Sep 16 11:36:10 2017 -0400
Committer: Ray DeCampo <ra...@decampo.org>
Committed: Sat Sep 16 11:36:10 2017 -0400

----------------------------------------------------------------------
 .../commons/math4/complex/Quaternion.java       | 465 -------------------
 .../commons/math4/complex/QuaternionTest.java   | 459 ------------------
 2 files changed, 924 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/commons-math/blob/e415b2f4/src/main/java/org/apache/commons/math4/complex/Quaternion.java
----------------------------------------------------------------------
diff --git a/src/main/java/org/apache/commons/math4/complex/Quaternion.java b/src/main/java/org/apache/commons/math4/complex/Quaternion.java
deleted file mode 100644
index f5f22cc..0000000
--- a/src/main/java/org/apache/commons/math4/complex/Quaternion.java
+++ /dev/null
@@ -1,465 +0,0 @@
-/*
- * 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.math4.complex;
-
-import java.io.Serializable;
-
-import org.apache.commons.math4.exception.DimensionMismatchException;
-import org.apache.commons.math4.exception.ZeroException;
-import org.apache.commons.math4.exception.util.LocalizedFormats;
-import org.apache.commons.math4.util.FastMath;
-import org.apache.commons.math4.util.MathUtils;
-import org.apache.commons.numbers.core.Precision;
-
-/**
- * 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
- */
-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 = scalar;
-        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 multiply(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 multiply(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();
-    }
-
-    /**
-     * Computes 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(this, 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();
-    }
-}

http://git-wip-us.apache.org/repos/asf/commons-math/blob/e415b2f4/src/test/java/org/apache/commons/math4/complex/QuaternionTest.java
----------------------------------------------------------------------
diff --git a/src/test/java/org/apache/commons/math4/complex/QuaternionTest.java b/src/test/java/org/apache/commons/math4/complex/QuaternionTest.java
deleted file mode 100644
index 06feaa5..0000000
--- a/src/test/java/org/apache/commons/math4/complex/QuaternionTest.java
+++ /dev/null
@@ -1,459 +0,0 @@
-/*
- * 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.math4.complex;
-
-import java.util.Random;
-
-import org.apache.commons.math4.complex.Quaternion;
-import org.apache.commons.math4.exception.DimensionMismatchException;
-import org.apache.commons.math4.exception.ZeroException;
-import org.apache.commons.math4.geometry.euclidean.threed.Rotation;
-import org.apache.commons.math4.geometry.euclidean.threed.RotationConvention;
-import org.apache.commons.math4.geometry.euclidean.threed.Cartesian3D;
-import org.apache.commons.math4.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
-    public final void testAccessors3() {
-        final double q0 = 2;
-        final double q1 = 5.4;
-        final double q2 = 17;
-        final double q3 = 0.0005;
-        final Quaternion q = new Quaternion(q0, new double[] { 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.multiply(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 Cartesian3D vectorA = new Cartesian3D(qA.getVectorPart());
-        final Cartesian3D vectorB = new Cartesian3D(qB.getVectorPart());
-        final Cartesian3D vectorResult = new Cartesian3D(qResult.getVectorPart());
-
-        final double scalarPartRef = qA.getScalarPart() * qB.getScalarPart() - Cartesian3D.dotProduct(vectorA, vectorB);
-
-        Assert.assertEquals(scalarPartRef, qResult.getScalarPart(), EPS);
-
-        final Cartesian3D vectorPartRef = ((vectorA.scalarMultiply(qB.getScalarPart())).add(vectorB.scalarMultiply(qA
-                .getScalarPart()))).add(Cartesian3D.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 = qB.getConjugate().multiply(qA.getConjugate());
-        final Quaternion productOfConjugate = (qA.multiply(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.multiply(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 = -Cartesian3D.dotProduct(new Cartesian3D(vectorQ), new Cartesian3D(vector));
-        Assert.assertEquals(scalarPartRefQxV, qResultQxV.getScalarPart(), EPS);
-
-        final Cartesian3D vectorPartRefQxV = (new Cartesian3D(vector).scalarMultiply(quaternion.getScalarPart())).add(Cartesian3D
-                .crossProduct(new Cartesian3D(vectorQ), new Cartesian3D(vector)));
-        final double normQxV = (new Cartesian3D(vectorResultQxV).subtract(vectorPartRefQxV)).getNorm();
-        Assert.assertEquals(0, normQxV, EPS);
-
-        // Case : Product between a vector and a quaternion : VxQ
-
-        final Quaternion qResultVxQ = Quaternion.multiply(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 = -Cartesian3D.dotProduct(new Cartesian3D(vectorQ), new Cartesian3D(vector));
-        Assert.assertEquals(scalarPartRefVxQ, qResultVxQ.getScalarPart(), EPS);
-
-        final Cartesian3D vectorPartRefVxQ = (new Cartesian3D(vector).scalarMultiply(quaternion.getScalarPart())).add(Cartesian3D
-                .crossProduct(new Cartesian3D(vector), new Cartesian3D(vectorQ)));
-        final double normVxQ = (new Cartesian3D(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 actual1 = Quaternion.dotProduct(q1, q2);
-        final double actual2 = q1.dotProduct(q2);
-
-        Assert.assertEquals(expected, actual1, EPS);
-        Assert.assertEquals(expected, actual2, 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 qa = Quaternion.add(q1, q2);
-        final Quaternion qb = q1.add(q2);
-
-        Assert.assertEquals(w, qa.getQ0(), EPS);
-        Assert.assertEquals(x, qa.getQ1(), EPS);
-        Assert.assertEquals(y, qa.getQ2(), EPS);
-        Assert.assertEquals(z, qa.getQ3(), EPS);
-
-        Assert.assertEquals(w, qb.getQ0(), EPS);
-        Assert.assertEquals(x, qb.getQ1(), EPS);
-        Assert.assertEquals(y, qb.getQ2(), EPS);
-        Assert.assertEquals(z, qb.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 qa = Quaternion.subtract(q1, q2);
-        final Quaternion qb = q1.subtract(q2);
-
-        Assert.assertEquals(w, qa.getQ0(), EPS);
-        Assert.assertEquals(x, qa.getQ1(), EPS);
-        Assert.assertEquals(y, qa.getQ2(), EPS);
-        Assert.assertEquals(z, qa.getQ3(), EPS);
-
-        Assert.assertEquals(w, qb.getQ0(), EPS);
-        Assert.assertEquals(x, qb.getQ1(), EPS);
-        Assert.assertEquals(y, qb.getQ2(), EPS);
-        Assert.assertEquals(z, qb.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(FastMath.sqrt(30), norm, 0);
-
-        final double normSquareRef = Quaternion.multiply(q, q.getConjugate()).getScalarPart();
-        Assert.assertEquals(FastMath.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(RotationConvention.VECTOR_OPERATOR).getX(),
-                                rot.getAxis(RotationConvention.VECTOR_OPERATOR).getX(),
-                                COMPARISON_EPS);
-            Assert.assertEquals(rot.getAxis(RotationConvention.VECTOR_OPERATOR).getY(),
-                                rot.getAxis(RotationConvention.VECTOR_OPERATOR).getY(),
-                                COMPARISON_EPS);
-            Assert.assertEquals(rot.getAxis(RotationConvention.VECTOR_OPERATOR).getZ(),
-                                rot.getAxis(RotationConvention.VECTOR_OPERATOR).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.multiply(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]"));
-    }
-}