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 * @version $Id: FirstOrderIntegrator.java 1416643 2012-12-03 19:37:14Z tn $
037 * @since 1.2
038 */
039
040public interface FirstOrderIntegrator extends ODEIntegrator {
041
042  /** Integrate the differential equations up to the given time.
043   * <p>This method solves an Initial Value Problem (IVP).</p>
044   * <p>Since this method stores some internal state variables made
045   * available in its public interface during integration ({@link
046   * #getCurrentSignedStepsize()}), it is <em>not</em> thread-safe.</p>
047   * @param equations differential equations to integrate
048   * @param t0 initial time
049   * @param y0 initial value of the state vector at t0
050   * @param t target time for the integration
051   * (can be set to a value smaller than <code>t0</code> for backward integration)
052   * @param y placeholder where to put the state vector at each successful
053   *  step (and hence at the end of integration), can be the same object as y0
054   * @return stop time, will be the same as target time if integration reached its
055   * target, but may be different if some {@link
056   * org.apache.commons.math3.ode.events.EventHandler} stops it at some point.
057   * @exception DimensionMismatchException if arrays dimension do not match equations settings
058   * @exception NumberIsTooSmallException if integration step is too small
059   * @exception MaxCountExceededException if the number of functions evaluations is exceeded
060   * @exception NoBracketingException if the location of an event cannot be bracketed
061   */
062  double integrate (FirstOrderDifferentialEquations equations,
063                    double t0, double[] y0, double t, double[] y)
064      throws DimensionMismatchException, NumberIsTooSmallException,
065             MaxCountExceededException, NoBracketingException;
066
067}