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/* * 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.analysis.solvers; import org.apache.commons.math3.analysis.UnivariateFunction; /** * Interface for (univariate real) rootfinding algorithms. * Implementations will search for only one zero in the given interval. * * This class is not intended for use outside of the Apache Commons Math * library, regular user should rely on more specific interfaces like * {@link UnivariateSolver}, {@link PolynomialSolver} or {@link * DifferentiableUnivariateSolver}. * @param <FUNC> Type of function to solve. * * @since 3.0 * @version $Id: BaseUnivariateSolver.java 1364387 2012-07-22 18:14:11Z tn $ * @see UnivariateSolver * @see PolynomialSolver * @see DifferentiableUnivariateSolver */ public interface BaseUnivariateSolver<FUNC extends UnivariateFunction> { /** * Get the maximum number of function evaluations. * * @return the maximum number of function evaluations. */ int getMaxEvaluations(); /** * Get the number of evaluations of the objective function. * The number of evaluations corresponds to the last call to the * {@code optimize} method. It is 0 if the method has not been * called yet. * * @return the number of evaluations of the objective function. */ int getEvaluations(); /** * Get the absolute accuracy of the solver. Solutions returned by the * solver should be accurate to this tolerance, i.e., if ε is the * absolute accuracy of the solver and {@code v} is a value returned by * one of the {@code solve} methods, then a root of the function should * exist somewhere in the interval ({@code v} - ε, {@code v} + ε). * * @return the absolute accuracy. */ double getAbsoluteAccuracy(); /** * Get the relative accuracy of the solver. The contract for relative * accuracy is the same as {@link #getAbsoluteAccuracy()}, but using * relative, rather than absolute error. If ρ is the relative accuracy * configured for a solver and {@code v} is a value returned, then a root * of the function should exist somewhere in the interval * ({@code v} - ρ {@code v}, {@code v} + ρ {@code v}). * * @return the relative accuracy. */ double getRelativeAccuracy(); /** * Get the function value accuracy of the solver. If {@code v} is * a value returned by the solver for a function {@code f}, * then by contract, {@code |f(v)|} should be less than or equal to * the function value accuracy configured for the solver. * * @return the function value accuracy. */ double getFunctionValueAccuracy(); /** * Solve for a zero root in the given interval. * A solver may require that the interval brackets a single zero root. * Solvers that do require bracketing should be able to handle the case * where one of the endpoints is itself a root. * * @param maxEval Maximum number of evaluations. * @param f Function to solve. * @param min Lower bound for the interval. * @param max Upper bound for the interval. * @return a value where the function is zero. * @throws org.apache.commons.math3.exception.MathIllegalArgumentException * if the arguments do not satisfy the requirements specified by the solver. * @throws org.apache.commons.math3.exception.TooManyEvaluationsException if * the allowed number of evaluations is exceeded. */ double solve(int maxEval, FUNC f, double min, double max); /** * Solve for a zero in the given interval, start at {@code startValue}. * A solver may require that the interval brackets a single zero root. * Solvers that do require bracketing should be able to handle the case * where one of the endpoints is itself a root. * * @param maxEval Maximum number of evaluations. * @param f Function to solve. * @param min Lower bound for the interval. * @param max Upper bound for the interval. * @param startValue Start value to use. * @return a value where the function is zero. * @throws org.apache.commons.math3.exception.MathIllegalArgumentException * if the arguments do not satisfy the requirements specified by the solver. * @throws org.apache.commons.math3.exception.TooManyEvaluationsException if * the allowed number of evaluations is exceeded. */ double solve(int maxEval, FUNC f, double min, double max, double startValue); /** * Solve for a zero in the vicinity of {@code startValue}. * * @param f Function to solve. * @param startValue Start value to use. * @return a value where the function is zero. * @param maxEval Maximum number of evaluations. * @throws org.apache.commons.math3.exception.MathIllegalArgumentException * if the arguments do not satisfy the requirements specified by the solver. * @throws org.apache.commons.math3.exception.TooManyEvaluationsException if * the allowed number of evaluations is exceeded. */ double solve(int maxEval, FUNC f, double startValue); }