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.math3.ode; 19 20 import org.apache.commons.math3.exception.DimensionMismatchException; 21 import org.apache.commons.math3.exception.MaxCountExceededException; 22 23 /** 24 * This interface allows users to add secondary differential equations to a primary set of 25 * differential equations. 26 * 27 * <p>In some cases users may need to integrate some problem-specific equations along with a primary 28 * set of differential equations. One example is optimal control where adjoined parameters linked to 29 * the minimized hamiltonian must be integrated. 30 * 31 * <p>This interface allows users to add such equations to a primary set of {@link 32 * FirstOrderDifferentialEquations first order differential equations} thanks to the {@link 33 * ExpandableStatefulODE#addSecondaryEquations(SecondaryEquations)} method. 34 * 35 * @see ExpandableStatefulODE 36 * @since 3.0 37 */ 38 public interface SecondaryEquations { 39 40 /** 41 * Get the dimension of the secondary state parameters. 42 * 43 * @return dimension of the secondary state parameters 44 */ getDimension()45 int getDimension(); 46 47 /** 48 * Compute the derivatives related to the secondary state parameters. 49 * 50 * @param t current value of the independent <I>time</I> variable 51 * @param primary array containing the current value of the primary state vector 52 * @param primaryDot array containing the derivative of the primary state vector 53 * @param secondary array containing the current value of the secondary state vector 54 * @param secondaryDot placeholder array where to put the derivative of the secondary state 55 * vector 56 * @exception MaxCountExceededException if the number of functions evaluations is exceeded 57 * @exception DimensionMismatchException if arrays dimensions do not match equations settings 58 */ computeDerivatives( double t, double[] primary, double[] primaryDot, double[] secondary, double[] secondaryDot)59 void computeDerivatives( 60 double t, 61 double[] primary, 62 double[] primaryDot, 63 double[] secondary, 64 double[] secondaryDot) 65 throws MaxCountExceededException, DimensionMismatchException; 66 } 67