/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.math3.ode; import org.apache.commons.math3.exception.DimensionMismatchException; import org.apache.commons.math3.exception.MaxCountExceededException; /** * This interface allows users to add secondary differential equations to a primary set of * differential equations. * *

In some cases users may need to integrate some problem-specific equations along with a primary * set of differential equations. One example is optimal control where adjoined parameters linked to * the minimized hamiltonian must be integrated. * *

This interface allows users to add such equations to a primary set of {@link * FirstOrderDifferentialEquations first order differential equations} thanks to the {@link * ExpandableStatefulODE#addSecondaryEquations(SecondaryEquations)} method. * * @see ExpandableStatefulODE * @since 3.0 */ public interface SecondaryEquations { /** * Get the dimension of the secondary state parameters. * * @return dimension of the secondary state parameters */ int getDimension(); /** * Compute the derivatives related to the secondary state parameters. * * @param t current value of the independent time variable * @param primary array containing the current value of the primary state vector * @param primaryDot array containing the derivative of the primary state vector * @param secondary array containing the current value of the secondary state vector * @param secondaryDot placeholder array where to put the derivative of the secondary state * vector * @exception MaxCountExceededException if the number of functions evaluations is exceeded * @exception DimensionMismatchException if arrays dimensions do not match equations settings */ void computeDerivatives( double t, double[] primary, double[] primaryDot, double[] secondary, double[] secondaryDot) throws MaxCountExceededException, DimensionMismatchException; }