001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package org.apache.commons.math3.ode; 019 020import org.apache.commons.math3.exception.DimensionMismatchException; 021import org.apache.commons.math3.exception.MaxCountExceededException; 022import org.apache.commons.math3.exception.NoBracketingException; 023import org.apache.commons.math3.exception.NumberIsTooSmallException; 024 025/** This interface represents a first order integrator for 026 * differential equations. 027 028 * <p>The classes which are devoted to solve first order differential 029 * equations should implement this interface. The problems which can 030 * be handled should implement the {@link 031 * FirstOrderDifferentialEquations} interface.</p> 032 * 033 * @see FirstOrderDifferentialEquations 034 * @see org.apache.commons.math3.ode.sampling.StepHandler 035 * @see org.apache.commons.math3.ode.events.EventHandler 036 * @since 1.2 037 */ 038 039public interface FirstOrderIntegrator extends ODEIntegrator { 040 041 /** Integrate the differential equations up to the given time. 042 * <p>This method solves an Initial Value Problem (IVP).</p> 043 * <p>Since this method stores some internal state variables made 044 * available in its public interface during integration ({@link 045 * #getCurrentSignedStepsize()}), it is <em>not</em> thread-safe.</p> 046 * @param equations differential equations to integrate 047 * @param t0 initial time 048 * @param y0 initial value of the state vector at t0 049 * @param t target time for the integration 050 * (can be set to a value smaller than <code>t0</code> for backward integration) 051 * @param y placeholder where to put the state vector at each successful 052 * step (and hence at the end of integration), can be the same object as y0 053 * @return stop time, will be the same as target time if integration reached its 054 * target, but may be different if some {@link 055 * org.apache.commons.math3.ode.events.EventHandler} stops it at some point. 056 * @exception DimensionMismatchException if arrays dimension do not match equations settings 057 * @exception NumberIsTooSmallException if integration step is too small 058 * @exception MaxCountExceededException if the number of functions evaluations is exceeded 059 * @exception NoBracketingException if the location of an event cannot be bracketed 060 */ 061 double integrate (FirstOrderDifferentialEquations equations, 062 double t0, double[] y0, double t, double[] y) 063 throws DimensionMismatchException, NumberIsTooSmallException, 064 MaxCountExceededException, NoBracketingException; 065 066}