Java tutorial
/* * 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; import org.apache.commons.math3.exception.DimensionMismatchException; import org.apache.commons.math3.exception.MaxCountExceededException; /** This interface represents a first order differential equations set. * * <p>This interface should be implemented by all real first order * differential equation problems before they can be handled by the * integrators {@link FirstOrderIntegrator#integrate} method.</p> * * <p>A first order differential equations problem, as seen by an * integrator is the time derivative <code>dY/dt</code> of a state * vector <code>Y</code>, both being one dimensional arrays. From the * integrator point of view, this derivative depends only on the * current time <code>t</code> and on the state vector * <code>Y</code>.</p> * * <p>For real problems, the derivative depends also on parameters * that do not belong to the state vector (dynamical model constants * for example). These constants are completely outside of the scope * of this interface, the classes that implement it are allowed to * handle them as they want.</p> * * @see FirstOrderIntegrator * @see FirstOrderConverter * @see SecondOrderDifferentialEquations * * @version $Id: FirstOrderDifferentialEquations.java 1416643 2012-12-03 19:37:14Z tn $ * @since 1.2 */ public interface FirstOrderDifferentialEquations { /** Get the dimension of the problem. * @return dimension of the problem */ int getDimension(); /** Get the current time derivative of the state vector. * @param t current value of the independent <I>time</I> variable * @param y array containing the current value of the state vector * @param yDot placeholder array where to put the time derivative of the state vector * @exception MaxCountExceededException if the number of functions evaluations is exceeded * @exception DimensionMismatchException if arrays dimensions do not match equations settings */ void computeDerivatives(double t, double[] y, double[] yDot) throws MaxCountExceededException, DimensionMismatchException; }