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
023 /**
024 * This interface allows users to add secondary differential equations to a primary
025 * set of differential equations.
026 * <p>
027 * In some cases users may need to integrate some problem-specific equations along
028 * with a primary set of differential equations. One example is optimal control where
029 * adjoined parameters linked to the minimized hamiltonian must be integrated.
030 * </p>
031 * <p>
032 * This interface allows users to add such equations to a primary set of {@link
033 * FirstOrderDifferentialEquations first order differential equations}
034 * thanks to the {@link
035 * ExpandableStatefulODE#addSecondaryEquations(SecondaryEquations)}
036 * method.
037 * </p>
038 * @see ExpandableStatefulODE
039 * @version $Id: SecondaryEquations.java 1416643 2012-12-03 19:37:14Z tn $
040 * @since 3.0
041 */
042 public interface SecondaryEquations {
043
044 /** Get the dimension of the secondary state parameters.
045 * @return dimension of the secondary state parameters
046 */
047 int getDimension();
048
049 /** Compute the derivatives related to the secondary state parameters.
050 * @param t current value of the independent <I>time</I> variable
051 * @param primary array containing the current value of the primary state vector
052 * @param primaryDot array containing the derivative of the primary state vector
053 * @param secondary array containing the current value of the secondary state vector
054 * @param secondaryDot placeholder array where to put the derivative of the secondary state vector
055 * @exception MaxCountExceededException if the number of functions evaluations is exceeded
056 * @exception DimensionMismatchException if arrays dimensions do not match equations settings
057 */
058 void computeDerivatives(double t, double[] primary, double[] primaryDot,
059 double[] secondary, double[] secondaryDot)
060 throws MaxCountExceededException, DimensionMismatchException;
061
062 }