| /* |
| * 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.differentiation; |
| |
| import org.junit.Assert; |
| |
| import org.apache.commons.math3.TestUtils; |
| import org.apache.commons.math3.util.FastMath; |
| import org.junit.Test; |
| |
| |
| /** |
| * Test for class {@link JacobianFunction}. |
| */ |
| public class JacobianFunctionTest { |
| |
| @Test |
| public void testSphere() { |
| SphereMapping f = new SphereMapping(10.0); |
| JacobianFunction j = new JacobianFunction(f); |
| for (double latitude = -1.5; latitude < 1.5; latitude += 0.1) { |
| for (double longitude = -3.1; longitude < 3.1; longitude += 0.1) { |
| double[] point = new double[] { latitude, longitude }; |
| double[][] referenceJacobian = f.jacobian(point); |
| double[][] testJacobian = j.value(point); |
| Assert.assertEquals(referenceJacobian.length, testJacobian.length); |
| for (int i = 0; i < 3; ++i) { |
| TestUtils.assertEquals(referenceJacobian[i], testJacobian[i], 2.0e-15); |
| } |
| } |
| } |
| } |
| |
| /* Maps (latitude, longitude) to (x, y, z) */ |
| private static class SphereMapping implements MultivariateDifferentiableVectorFunction { |
| |
| private final double radius; |
| |
| public SphereMapping(final double radius) { |
| this.radius = radius; |
| } |
| |
| public double[] value(double[] point) { |
| final double cLat = FastMath.cos(point[0]); |
| final double sLat = FastMath.sin(point[0]); |
| final double cLon = FastMath.cos(point[1]); |
| final double sLon = FastMath.sin(point[1]); |
| return new double[] { |
| radius * cLon * cLat, |
| radius * sLon * cLat, |
| radius * sLat |
| }; |
| } |
| |
| public DerivativeStructure[] value(DerivativeStructure[] point) { |
| final DerivativeStructure cLat = point[0].cos(); |
| final DerivativeStructure sLat = point[0].sin(); |
| final DerivativeStructure cLon = point[1].cos(); |
| final DerivativeStructure sLon = point[1].sin(); |
| return new DerivativeStructure[] { |
| cLon.multiply(cLat).multiply(radius), |
| sLon.multiply(cLat).multiply(radius), |
| sLat.multiply(radius) |
| }; |
| } |
| |
| public double[][] jacobian(double[] point) { |
| final double cLat = FastMath.cos(point[0]); |
| final double sLat = FastMath.sin(point[0]); |
| final double cLon = FastMath.cos(point[1]); |
| final double sLon = FastMath.sin(point[1]); |
| return new double[][] { |
| { -radius * cLon * sLat, -radius * sLon * cLat }, |
| { -radius * sLon * sLat, radius * cLon * cLat }, |
| { radius * cLat, 0 } |
| }; |
| } |
| |
| } |
| |
| } |