| /* |
| * 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.optim.linear; |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| |
| import org.apache.commons.math4.exception.TooManyIterationsException; |
| import org.apache.commons.math4.optim.OptimizationData; |
| import org.apache.commons.math4.optim.PointValuePair; |
| import org.apache.commons.math4.optim.nonlinear.scalar.MultivariateOptimizer; |
| |
| /** |
| * Base class for implementing linear optimizers. |
| * |
| * @since 3.1 |
| */ |
| public abstract class LinearOptimizer |
| extends MultivariateOptimizer { |
| /** |
| * Linear objective function. |
| */ |
| private LinearObjectiveFunction function; |
| /** |
| * Linear constraints. |
| */ |
| private Collection<LinearConstraint> linearConstraints; |
| /** |
| * Whether to restrict the variables to non-negative values. |
| */ |
| private boolean nonNegative; |
| |
| /** |
| * Simple constructor with default settings. |
| * |
| */ |
| protected LinearOptimizer() { |
| super(null); // No convergence checker. |
| } |
| |
| /** |
| * @return {@code true} if the variables are restricted to non-negative values. |
| */ |
| protected boolean isRestrictedToNonNegative() { |
| return nonNegative; |
| } |
| |
| /** |
| * @return the optimization type. |
| */ |
| protected LinearObjectiveFunction getFunction() { |
| return function; |
| } |
| |
| /** |
| * @return the optimization type. |
| */ |
| protected Collection<LinearConstraint> getConstraints() { |
| return Collections.unmodifiableCollection(linearConstraints); |
| } |
| |
| /** |
| * {@inheritDoc} |
| * |
| * @param optData Optimization data. In addition to those documented in |
| * {@link MultivariateOptimizer#parseOptimizationData(OptimizationData[]) |
| * MultivariateOptimizer}, this method will register the following data: |
| * <ul> |
| * <li>{@link LinearObjectiveFunction}</li> |
| * <li>{@link LinearConstraintSet}</li> |
| * <li>{@link NonNegativeConstraint}</li> |
| * </ul> |
| * @return {@inheritDoc} |
| * @throws TooManyIterationsException if the maximal number of |
| * iterations is exceeded. |
| */ |
| @Override |
| public PointValuePair optimize(OptimizationData... optData) |
| throws TooManyIterationsException { |
| // Set up base class and perform computation. |
| return super.optimize(optData); |
| } |
| |
| /** |
| * Scans the list of (required and optional) optimization data that |
| * characterize the problem. |
| * |
| * @param optData Optimization data. |
| * The following data will be looked for: |
| * <ul> |
| * <li>{@link LinearObjectiveFunction}</li> |
| * <li>{@link LinearConstraintSet}</li> |
| * <li>{@link NonNegativeConstraint}</li> |
| * </ul> |
| */ |
| @Override |
| protected void parseOptimizationData(OptimizationData... optData) { |
| // Allow base class to register its own data. |
| super.parseOptimizationData(optData); |
| |
| // The existing values (as set by the previous call) are reused if |
| // not provided in the argument list. |
| for (OptimizationData data : optData) { |
| if (data instanceof LinearObjectiveFunction) { |
| function = (LinearObjectiveFunction) data; |
| continue; |
| } |
| if (data instanceof LinearConstraintSet) { |
| linearConstraints = ((LinearConstraintSet) data).getConstraints(); |
| continue; |
| } |
| if (data instanceof NonNegativeConstraint) { |
| nonNegative = ((NonNegativeConstraint) data).isRestrictedToNonNegative(); |
| continue; |
| } |
| } |
| } |
| } |