    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
    018    package org.apache.commons.math3.ode;
    019
    020    import org.apache.commons.math3.exception.DimensionMismatchException;
    021    import org.apache.commons.math3.exception.MaxCountExceededException;
    022    import org.apache.commons.math3.exception.NoBracketingException;
    023    import 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
    040    public 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    }