/* * 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 java.util.Collection; import org.apache.commons.math3.analysis.solvers.UnivariateSolver; import org.apache.commons.math3.ode.events.EventHandler; import org.apache.commons.math3.ode.sampling.StepHandler; /** * This interface defines the common parts shared by integrators * for first and second order differential equations. * @see FirstOrderIntegrator * @see SecondOrderIntegrator * @since 2.0 */ public interface ODEIntegrator { /** Get the name of the method. * @return name of the method */ String getName(); /** Add a step handler to this integrator. * <p>The handler will be called by the integrator for each accepted * step.</p> * @param handler handler for the accepted steps * @see #getStepHandlers() * @see #clearStepHandlers() * @since 2.0 */ void addStepHandler(StepHandler handler); /** Get all the step handlers that have been added to the integrator. * @return an unmodifiable collection of the added events handlers * @see #addStepHandler(StepHandler) * @see #clearStepHandlers() * @since 2.0 */ Collection<StepHandler> getStepHandlers(); /** Remove all the step handlers that have been added to the integrator. * @see #addStepHandler(StepHandler) * @see #getStepHandlers() * @since 2.0 */ void clearStepHandlers(); /** Add an event handler to the integrator. * Uses a default {@link UnivariateSolver} * with an absolute accuracy equal to the given convergence threshold, * as root-finding algorithm to detect the state events. * @param handler event handler * @param maxCheckInterval maximal time interval between switching * function checks (this interval prevents missing sign changes in * case the integration steps becomes very large) * @param convergence convergence threshold in the event time search * @param maxIterationCount upper limit of the iteration count in * the event time search * @see #getEventHandlers() * @see #clearEventHandlers() */ void addEventHandler(EventHandler handler, double maxCheckInterval, double convergence, int maxIterationCount); /** Add an event handler to the integrator. * @param handler event handler * @param maxCheckInterval maximal time interval between switching * function checks (this interval prevents missing sign changes in * case the integration steps becomes very large) * @param convergence convergence threshold in the event time search * @param maxIterationCount upper limit of the iteration count in * the event time search * @param solver The root-finding algorithm to use to detect the state * events. * @see #getEventHandlers() * @see #clearEventHandlers() */ void addEventHandler(EventHandler handler, double maxCheckInterval, double convergence, int maxIterationCount, UnivariateSolver solver); /** Get all the event handlers that have been added to the integrator. * @return an unmodifiable collection of the added events handlers * @see #addEventHandler(EventHandler, double, double, int) * @see #clearEventHandlers() */ Collection<EventHandler> getEventHandlers(); /** Remove all the event handlers that have been added to the integrator. * @see #addEventHandler(EventHandler, double, double, int) * @see #getEventHandlers() */ void clearEventHandlers(); /** Get the current value of the step start time t<sub>i</sub>. * <p>This method can be called during integration (typically by * the object implementing the {@link FirstOrderDifferentialEquations * differential equations} problem) if the value of the current step that * is attempted is needed.</p> * <p>The result is undefined if the method is called outside of * calls to <code>integrate</code>.</p> * @return current value of the step start time t<sub>i</sub> */ double getCurrentStepStart(); /** Get the current signed value of the integration stepsize. * <p>This method can be called during integration (typically by * the object implementing the {@link FirstOrderDifferentialEquations * differential equations} problem) if the signed value of the current stepsize * that is tried is needed.</p> * <p>The result is undefined if the method is called outside of * calls to <code>integrate</code>.</p> * @return current signed value of the stepsize */ double getCurrentSignedStepsize(); /** Set the maximal number of differential equations function evaluations. * <p>The purpose of this method is to avoid infinite loops which can occur * for example when stringent error constraints are set or when lots of * discrete events are triggered, thus leading to many rejected steps.</p> * @param maxEvaluations maximal number of function evaluations (negative * values are silently converted to maximal integer value, thus representing * almost unlimited evaluations) */ void setMaxEvaluations(int maxEvaluations); /** Get the maximal number of functions evaluations. * @return maximal number of functions evaluations */ int getMaxEvaluations(); /** Get the number of evaluations of the differential equations function. * <p> * The number of evaluations corresponds to the last call to the * <code>integrate</code> method. It is 0 if the method has not been called yet. * </p> * @return number of evaluations of the differential equations function */ int getEvaluations(); }