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Java example source code file (StepInterpolatorTestUtils.java)
The StepInterpolatorTestUtils.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.ode.sampling; import org.apache.commons.math3.RealFieldElement; import org.apache.commons.math3.exception.DimensionMismatchException; import org.apache.commons.math3.exception.MaxCountExceededException; import org.apache.commons.math3.exception.NoBracketingException; import org.apache.commons.math3.exception.NumberIsTooSmallException; import org.apache.commons.math3.ode.FieldExpandableODE; import org.apache.commons.math3.ode.FirstOrderFieldIntegrator; import org.apache.commons.math3.ode.FieldODEStateAndDerivative; import org.apache.commons.math3.ode.FirstOrderIntegrator; import org.apache.commons.math3.ode.TestFieldProblemAbstract; import org.apache.commons.math3.ode.TestProblemAbstract; import org.apache.commons.math3.util.FastMath; import org.junit.Assert; public class StepInterpolatorTestUtils { public static void checkDerivativesConsistency(final FirstOrderIntegrator integrator, final TestProblemAbstract problem, final double finiteDifferencesRatio, final double threshold) throws DimensionMismatchException, NumberIsTooSmallException, MaxCountExceededException, NoBracketingException { integrator.addStepHandler(new StepHandler() { public void handleStep(StepInterpolator interpolator, boolean isLast) throws MaxCountExceededException { final double dt = interpolator.getCurrentTime() - interpolator.getPreviousTime(); final double h = finiteDifferencesRatio * dt; final double t = interpolator.getCurrentTime() - 0.3 * dt; if (FastMath.abs(h) < 10 * FastMath.ulp(t)) { return; } interpolator.setInterpolatedTime(t - 4 * h); final double[] yM4h = interpolator.getInterpolatedState().clone(); interpolator.setInterpolatedTime(t - 3 * h); final double[] yM3h = interpolator.getInterpolatedState().clone(); interpolator.setInterpolatedTime(t - 2 * h); final double[] yM2h = interpolator.getInterpolatedState().clone(); interpolator.setInterpolatedTime(t - h); final double[] yM1h = interpolator.getInterpolatedState().clone(); interpolator.setInterpolatedTime(t + h); final double[] yP1h = interpolator.getInterpolatedState().clone(); interpolator.setInterpolatedTime(t + 2 * h); final double[] yP2h = interpolator.getInterpolatedState().clone(); interpolator.setInterpolatedTime(t + 3 * h); final double[] yP3h = interpolator.getInterpolatedState().clone(); interpolator.setInterpolatedTime(t + 4 * h); final double[] yP4h = interpolator.getInterpolatedState().clone(); interpolator.setInterpolatedTime(t); final double[] yDot = interpolator.getInterpolatedDerivatives(); for (int i = 0; i < yDot.length; ++i) { final double approYDot = ( -3 * (yP4h[i] - yM4h[i]) + 32 * (yP3h[i] - yM3h[i]) + -168 * (yP2h[i] - yM2h[i]) + 672 * (yP1h[i] - yM1h[i])) / (840 * h); Assert.assertEquals("" + (approYDot - yDot[i]), approYDot, yDot[i], threshold); } } public void init(double t0, double[] y0, double t) { } }); integrator.integrate(problem, problem.getInitialTime(), problem.getInitialState(), problem.getFinalTime(), new double[problem.getDimension()]); } public static <T extends RealFieldElement Other Java examples (source code examples)Here is a short list of links related to this Java StepInterpolatorTestUtils.java source code file: |
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