| /* |
| * 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.math.optimization.linear; |
| |
| import java.util.Collection; |
| |
| import org.apache.commons.math.optimization.GoalType; |
| import org.apache.commons.math.optimization.OptimizationException; |
| import org.apache.commons.math.optimization.RealPointValuePair; |
| |
| /** |
| * This interface represents an optimization algorithm for linear problems. |
| * <p>Optimization algorithms find the input point set that either {@link GoalType |
| * maximize or minimize} an objective function. In the linear case the form of |
| * the function is restricted to |
| * <pre> |
| * c<sub>1</sub>x<sub>1</sub> + ... c<sub>n</sub>x<sub>n</sub> = v |
| * </pre> |
| * and there may be linear constraints too, of one of the forms: |
| * <ul> |
| * <li>c<sub>1</sub>x<sub>1</sub> + ... c<sub>n</sub>x<sub>n</sub> = v</li> |
| * <li>c<sub>1</sub>x<sub>1</sub> + ... c<sub>n</sub>x<sub>n</sub> <= v</li> |
| * <li>c<sub>1</sub>x<sub>1</sub> + ... c<sub>n</sub>x<sub>n</sub> >= v</li> |
| * <li>l<sub>1</sub>x<sub>1</sub> + ... l<sub>n</sub>x<sub>n</sub> + l<sub>cst</sub> = |
| * r<sub>1</sub>x<sub>1</sub> + ... r<sub>n</sub>x<sub>n</sub> + r<sub>cst</sub></li> |
| * <li>l<sub>1</sub>x<sub>1</sub> + ... l<sub>n</sub>x<sub>n</sub> + l<sub>cst</sub> <= |
| * r<sub>1</sub>x<sub>1</sub> + ... r<sub>n</sub>x<sub>n</sub> + r<sub>cst</sub></li> |
| * <li>l<sub>1</sub>x<sub>1</sub> + ... l<sub>n</sub>x<sub>n</sub> + l<sub>cst</sub> >= |
| * r<sub>1</sub>x<sub>1</sub> + ... r<sub>n</sub>x<sub>n</sub> + r<sub>cst</sub></li> |
| * </ul> |
| * where the c<sub>i</sub>, l<sub>i</sub> or r<sub>i</sub> are the coefficients of |
| * the constraints, the x<sub>i</sub> are the coordinates of the current point and |
| * v is the value of the constraint. |
| * </p> |
| * @version $Revision: 811685 $ $Date: 2009-09-05 19:36:48 +0200 (sam. 05 sept. 2009) $ |
| * @since 2.0 |
| */ |
| public interface LinearOptimizer { |
| |
| /** Set the maximal number of iterations of the algorithm. |
| * @param maxIterations maximal number of function calls |
| */ |
| void setMaxIterations(int maxIterations); |
| |
| /** Get the maximal number of iterations of the algorithm. |
| * @return maximal number of iterations |
| */ |
| int getMaxIterations(); |
| |
| /** Get the number of iterations realized by the algorithm. |
| * <p> |
| * The number of evaluations corresponds to the last call to the |
| * {@link #optimize(LinearObjectiveFunction, Collection, GoalType, boolean) optimize} |
| * method. It is 0 if the method has not been called yet. |
| * </p> |
| * @return number of iterations |
| */ |
| int getIterations(); |
| |
| /** Optimizes an objective function. |
| * @param f linear objective function |
| * @param constraints linear constraints |
| * @param goalType type of optimization goal: either {@link GoalType#MAXIMIZE} |
| * or {@link GoalType#MINIMIZE} |
| * @param restrictToNonNegative whether to restrict the variables to non-negative values |
| * @return point/value pair giving the optimal value for objective function |
| * @exception OptimizationException if no solution fulfilling the constraints |
| * can be found in the allowed number of iterations |
| */ |
| RealPointValuePair optimize(LinearObjectiveFunction f, Collection<LinearConstraint> constraints, |
| GoalType goalType, boolean restrictToNonNegative) |
| throws OptimizationException; |
| |
| } |