All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.apache.commons.math.optimization.linear.AbstractLinearOptimizer Maven / Gradle / Ivy

Go to download

The Math project is a library of lightweight, self-contained mathematics and statistics components addressing the most common practical problems not immediately available in the Java programming language or commons-lang.

There is a newer version: 2.2
Show newest version
/*
 * 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.MaxIterationsExceededException;
import org.apache.commons.math.optimization.GoalType;
import org.apache.commons.math.optimization.OptimizationException;
import org.apache.commons.math.optimization.RealPointValuePair;

/**
 * Base class for implementing linear optimizers.
 * 

This base class handles the boilerplate methods associated to thresholds * settings and iterations counters.

* @version $Revision: 786466 $ $Date: 2009-06-19 08:03:14 -0400 (Fri, 19 Jun 2009) $ * @since 2.0 * */ public abstract class AbstractLinearOptimizer implements LinearOptimizer { /** Default maximal number of iterations allowed. */ public static final int DEFAULT_MAX_ITERATIONS = 100; /** Maximal number of iterations allowed. */ private int maxIterations; /** Number of iterations already performed. */ private int iterations; /** Linear objective function. */ protected LinearObjectiveFunction f; /** Linear constraints. */ protected Collection constraints; /** Type of optimization goal: either {@link GoalType#MAXIMIZE} or {@link GoalType#MINIMIZE}. */ protected GoalType goalType; /** Whether to restrict the variables to non-negative values. */ protected boolean restrictToNonNegative; /** Simple constructor with default settings. *

The maximal number of evaluation is set to its default value.

*/ protected AbstractLinearOptimizer() { setMaxIterations(DEFAULT_MAX_ITERATIONS); } /** {@inheritDoc} */ public void setMaxIterations(int maxIterations) { this.maxIterations = maxIterations; } /** {@inheritDoc} */ public int getMaxIterations() { return maxIterations; } /** {@inheritDoc} */ public int getIterations() { return iterations; } /** Increment the iterations counter by 1. * @exception OptimizationException if the maximal number * of iterations is exceeded */ protected void incrementIterationsCounter() throws OptimizationException { if (++iterations > maxIterations) { throw new OptimizationException(new MaxIterationsExceededException(maxIterations)); } } /** {@inheritDoc} */ public RealPointValuePair optimize(final LinearObjectiveFunction f, final Collection constraints, final GoalType goalType, final boolean restrictToNonNegative) throws OptimizationException { // store linear problem characteristics this.f = f; this.constraints = constraints; this.goalType = goalType; this.restrictToNonNegative = restrictToNonNegative; iterations = 0; // solve the problem return doOptimize(); } /** Perform the bulk of optimization algorithm. * @return the 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 */ abstract protected RealPointValuePair doOptimize() throws OptimizationException; }




© 2015 - 2024 Weber Informatics LLC | Privacy Policy