home | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (HarmonicOscillatorTest.java)

This example Java source code file (HarmonicOscillatorTest.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

derivativestructure, eps, harmonicoscillator, harmonicoscillatortest, test, univariatefunction

The HarmonicOscillatorTest.java Java example source code

/*
 * 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.analysis.function;

import org.apache.commons.math3.analysis.UnivariateFunction;
import org.apache.commons.math3.analysis.differentiation.DerivativeStructure;
import org.apache.commons.math3.exception.DimensionMismatchException;
import org.apache.commons.math3.exception.NullArgumentException;
import org.apache.commons.math3.util.FastMath;
import org.apache.commons.math3.util.Precision;
import org.junit.Assert;
import org.junit.Test;

/**
 * Test for class {@link HarmonicOscillator}.
 */
public class HarmonicOscillatorTest {
    private final double EPS = Math.ulp(1d);

    @Test
    public void testSomeValues() {
        final double a = -1.2;
        final double w = 0.34;
        final double p = 5.6;
        final UnivariateFunction f = new HarmonicOscillator(a, w, p);

        final double d = 0.12345;
        for (int i = 0; i < 10; i++) {
            final double v = i * d;
            Assert.assertEquals(a * FastMath.cos(w * v + p), f.value(v), 0);
        }
    }

    @Test
    public void testDerivative() {
        final double a = -1.2;
        final double w = 0.34;
        final double p = 5.6;
        final HarmonicOscillator f = new HarmonicOscillator(a, w, p);

        for (int maxOrder = 0; maxOrder < 6; ++maxOrder) {
            final double d = 0.12345;
            for (int i = 0; i < 10; i++) {
                final double v = i * d;
                final DerivativeStructure h = f.value(new DerivativeStructure(1, maxOrder, 0, v));
                for (int k = 0; k <= maxOrder; ++k) {
                    final double trigo;
                    switch (k % 4) {
                        case 0:
                            trigo = +FastMath.cos(w * v + p);
                            break;
                        case 1:
                            trigo = -FastMath.sin(w * v + p);
                            break;
                        case 2:
                            trigo = -FastMath.cos(w * v + p);
                            break;
                        default:
                            trigo = +FastMath.sin(w * v + p);
                            break;
                    }
                    Assert.assertEquals(a * FastMath.pow(w, k) * trigo,
                                        h.getPartialDerivative(k),
                                        Precision.EPSILON);
                }
            }
        }
    }

    @Test(expected=NullArgumentException.class)
    public void testParametricUsage1() {
        final HarmonicOscillator.Parametric g = new HarmonicOscillator.Parametric();
        g.value(0, null);
    }

    @Test(expected=DimensionMismatchException.class)
    public void testParametricUsage2() {
        final HarmonicOscillator.Parametric g = new HarmonicOscillator.Parametric();
        g.value(0, new double[] {0});
    }

    @Test(expected=NullArgumentException.class)
    public void testParametricUsage3() {
        final HarmonicOscillator.Parametric g = new HarmonicOscillator.Parametric();
        g.gradient(0, null);
    }

    @Test(expected=DimensionMismatchException.class)
    public void testParametricUsage4() {
        final HarmonicOscillator.Parametric g = new HarmonicOscillator.Parametric();
        g.gradient(0, new double[] {0});
    }

    @Test
    public void testParametricValue() {
        final double amplitude = 2;
        final double omega = 3;
        final double phase = 4;
        final HarmonicOscillator f = new HarmonicOscillator(amplitude, omega, phase);

        final HarmonicOscillator.Parametric g = new HarmonicOscillator.Parametric();
        Assert.assertEquals(f.value(-1), g.value(-1, new double[] {amplitude, omega, phase}), 0);
        Assert.assertEquals(f.value(0), g.value(0, new double[] {amplitude, omega, phase}), 0);
        Assert.assertEquals(f.value(2), g.value(2, new double[] {amplitude, omega, phase}), 0);
    }

    @Test
    public void testParametricGradient() {
        final double amplitude = 2;
        final double omega = 3;
        final double phase = 4;
        final HarmonicOscillator.Parametric f = new HarmonicOscillator.Parametric();

        final double x = 1;
        final double[] grad = f.gradient(1, new double[] {amplitude, omega, phase});
        final double xTimesOmegaPlusPhase = omega * x + phase;
        final double a = FastMath.cos(xTimesOmegaPlusPhase);
        Assert.assertEquals(a, grad[0], EPS);
        final double w = -amplitude * x * FastMath.sin(xTimesOmegaPlusPhase);
        Assert.assertEquals(w, grad[1], EPS);
        final double p = -amplitude * FastMath.sin(xTimesOmegaPlusPhase);
        Assert.assertEquals(p, grad[2], EPS);
    }
}

Other Java examples (source code examples)

Here is a short list of links related to this Java HarmonicOscillatorTest.java source code file:



my book on functional programming

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.