1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package org.apache.commons.math.ode; 19 20 21 /** This interface represents a first order integrator for 22 * differential equations. 23 24 * <p>The classes which are devoted to solve first order differential 25 * equations should implement this interface. The problems which can 26 * be handled should implement the {@link 27 * FirstOrderDifferentialEquations} interface.</p> 28 * 29 * @see FirstOrderDifferentialEquations 30 * @see org.apache.commons.math.ode.sampling.StepHandler 31 * @see org.apache.commons.math.ode.events.EventHandler 32 * @version $Revision: 1073158 $ $Date: 2011-02-21 22:46:52 +0100 (lun. 21 févr. 2011) $ 33 * @since 1.2 34 */ 35 36 public interface FirstOrderIntegrator extends ODEIntegrator { 37 38 /** Integrate the differential equations up to the given time. 39 * <p>This method solves an Initial Value Problem (IVP).</p> 40 * <p>Since this method stores some internal state variables made 41 * available in its public interface during integration ({@link 42 * #getCurrentSignedStepsize()}), it is <em>not</em> thread-safe.</p> 43 * @param equations differential equations to integrate 44 * @param t0 initial time 45 * @param y0 initial value of the state vector at t0 46 * @param t target time for the integration 47 * (can be set to a value smaller than <code>t0</code> for backward integration) 48 * @param y placeholder where to put the state vector at each successful 49 * step (and hence at the end of integration), can be the same object as y0 50 * @return stop time, will be the same as target time if integration reached its 51 * target, but may be different if some {@link 52 * org.apache.commons.math.ode.events.EventHandler} stops it at some point. 53 * @throws DerivativeException this exception is propagated to the caller if 54 * the underlying user function triggers one 55 * @throws IntegratorException if the integrator cannot perform integration 56 */ integrate(FirstOrderDifferentialEquations equations, double t0, double[] y0, double t, double[] y)57 double integrate (FirstOrderDifferentialEquations equations, 58 double t0, double[] y0, 59 double t, double[] y) throws DerivativeException, IntegratorException; 60 61 } 62