1dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond/* 2dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * Licensed to the Apache Software Foundation (ASF) under one or more 3dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * contributor license agreements. See the NOTICE file distributed with 4dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * this work for additional information regarding copyright ownership. 5dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * The ASF licenses this file to You under the Apache License, Version 2.0 6dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * (the "License"); you may not use this file except in compliance with 7dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * the License. You may obtain a copy of the License at 8dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * 9dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * http://www.apache.org/licenses/LICENSE-2.0 10dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * 11dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * Unless required by applicable law or agreed to in writing, software 12dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * distributed under the License is distributed on an "AS IS" BASIS, 13dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * See the License for the specific language governing permissions and 15dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * limitations under the License. 16dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond */ 17dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 18dee0849a9704d532af0b550146cbafbaa6ee1d19Raymondpackage org.apache.commons.math.ode; 19dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 20dee0849a9704d532af0b550146cbafbaa6ee1d19Raymondimport org.apache.commons.math.ode.DerivativeException; 21dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 22dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond/** This interface represents a second order differential equations set. 23dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 24dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * <p>This interface should be implemented by all real second order 25dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * differential equation problems before they can be handled by the 26dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * integrators {@link SecondOrderIntegrator#integrate} method.</p> 27dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * 28dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * <p>A second order differential equations problem, as seen by an 29dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * integrator is the second time derivative <code>d2Y/dt^2</code> of a 30dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * state vector <code>Y</code>, both being one dimensional 31dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * arrays. From the integrator point of view, this derivative depends 32dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * only on the current time <code>t</code>, on the state vector 33dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * <code>Y</code> and on the first time derivative of the state 34dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * vector.</p> 35dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * 36dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * <p>For real problems, the derivative depends also on parameters 37dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * that do not belong to the state vector (dynamical model constants 38dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * for example). These constants are completely outside of the scope 39dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * of this interface, the classes that implement it are allowed to 40dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * handle them as they want.</p> 41dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * 42dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @see SecondOrderIntegrator 43dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @see FirstOrderConverter 44dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @see FirstOrderDifferentialEquations 45dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @version $Revision: 1073158 $ $Date: 2011-02-21 22:46:52 +0100 (lun. 21 févr. 2011) $ 46dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @since 1.2 47dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond */ 48dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 49dee0849a9704d532af0b550146cbafbaa6ee1d19Raymondpublic interface SecondOrderDifferentialEquations { 50dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 51dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond /** Get the dimension of the problem. 52dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @return dimension of the problem 53dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond */ 54dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond int getDimension(); 55dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 56dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond /** Get the current time derivative of the state vector. 57dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @param t current value of the independent <I>time</I> variable 58dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @param y array containing the current value of the state vector 59dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @param yDot array containing the current value of the first derivative 60dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * of the state vector 61dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @param yDDot placeholder array where to put the second time derivative 62dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * of the state vector 63dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @throws DerivativeException this user-defined exception should be used if an error is 64dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * is triggered by user code 65dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond */ 66dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond void computeSecondDerivatives(double t, double[] y, double[] yDot, double[] yDDot) 67dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond throws DerivativeException; 68dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 69dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond} 70