| /* |
| * 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.math4.legacy.ode; |
| |
| import java.util.Collection; |
| |
| import org.apache.commons.math4.legacy.core.RealFieldElement; |
| import org.apache.commons.math4.legacy.analysis.solvers.BracketedRealFieldUnivariateSolver; |
| import org.apache.commons.math4.legacy.exception.MaxCountExceededException; |
| import org.apache.commons.math4.legacy.exception.NoBracketingException; |
| import org.apache.commons.math4.legacy.exception.NumberIsTooSmallException; |
| import org.apache.commons.math4.legacy.ode.events.FieldEventHandler; |
| import org.apache.commons.math4.legacy.ode.sampling.FieldStepHandler; |
| |
| /** This interface represents a first order integrator for |
| * differential equations. |
| |
| * <p>The classes which are devoted to solve first order differential |
| * equations should implement this interface. The problems which can |
| * be handled should implement the {@link |
| * FirstOrderDifferentialEquations} interface.</p> |
| * |
| * @see FirstOrderFieldDifferentialEquations |
| * @param <T> the type of the field elements |
| * @since 3.6 |
| */ |
| |
| public interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>> { |
| |
| /** 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() |
| */ |
| void addStepHandler(FieldStepHandler<T> handler); |
| |
| /** Get all the step handlers that have been added to the integrator. |
| * @return an unmodifiable collection of the added events handlers |
| * @see #addStepHandler(FieldStepHandler) |
| * @see #clearStepHandlers() |
| */ |
| Collection<FieldStepHandler<T>> getStepHandlers(); |
| |
| /** Remove all the step handlers that have been added to the integrator. |
| * @see #addStepHandler(FieldStepHandler) |
| * @see #getStepHandlers() |
| */ |
| void clearStepHandlers(); |
| |
| /** Add an event handler to the integrator. |
| * <p> |
| * The default solver is a 5<sup>th</sup> order {@link |
| * org.apache.commons.math4.legacy.analysis.solvers.FieldBracketingNthOrderBrentSolver}. |
| * </p> |
| * @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 events. |
| * @see #addEventHandler(FieldEventHandler, double, double, int, |
| * org.apache.commons.math4.legacy.analysis.solvers.BracketedRealFieldUnivariateSolver) |
| * @see #getEventHandlers() |
| * @see #clearEventHandlers() |
| */ |
| void addEventHandler(FieldEventHandler<T> 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 events. |
| * @param solver solver to use to locate the event |
| * @see #addEventHandler(FieldEventHandler, double, double, int) |
| * @see #getEventHandlers() |
| * @see #clearEventHandlers() |
| */ |
| void addEventHandler(FieldEventHandler<T> handler, double maxCheckInterval, |
| double convergence, int maxIterationCount, |
| BracketedRealFieldUnivariateSolver<T> solver); |
| |
| /** Get all the event handlers that have been added to the integrator. |
| * @return an unmodifiable collection of the added events handlers |
| * @see #addEventHandler(FieldEventHandler, double, double, int) |
| * @see #clearEventHandlers() |
| */ |
| Collection<FieldEventHandler<T>> getEventHandlers(); |
| |
| /** Remove all the event handlers that have been added to the integrator. |
| * @see #addEventHandler(FieldEventHandler, 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 state at step start time t<sub>i</sub> |
| */ |
| FieldODEStateAndDerivative<T> 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 |
| */ |
| T 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(); |
| |
| /** Integrate the differential equations up to the given time. |
| * <p>This method solves an Initial Value Problem (IVP).</p> |
| * <p>Since this method stores some internal state variables made |
| * available in its public interface during integration ({@link |
| * #getCurrentSignedStepsize()}), it is <em>not</em> thread-safe.</p> |
| * @param equations differential equations to integrate |
| * @param initialState initial state (time, primary and secondary state vectors) |
| * @param finalTime target time for the integration |
| * (can be set to a value smaller than {@code t0} for backward integration) |
| * @return final state, its time will be the same as {@code finalTime} if |
| * integration reached its target, but may be different if some {@link |
| * org.apache.commons.math4.legacy.ode.events.FieldEventHandler} stops it at some point. |
| * @exception NumberIsTooSmallException if integration step is too small |
| * @exception MaxCountExceededException if the number of functions evaluations is exceeded |
| * @exception NoBracketingException if the location of an event cannot be bracketed |
| */ |
| FieldODEStateAndDerivative<T> integrate(FieldExpandableODE<T> equations, |
| FieldODEState<T> initialState, T finalTime) |
| throws NumberIsTooSmallException, MaxCountExceededException, NoBracketingException; |
| |
| } |