| /* |
| * 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.genetics; |
| |
| import org.apache.commons.math4.exception.NumberIsTooSmallException; |
| |
| /** |
| * Stops after a fixed number of generations. |
| * <p> |
| * Each time {@link #isSatisfied(Population)} is invoked, a generation counter |
| * is incremented. Once the counter reaches the configured |
| * {@code maxGenerations} value, {@link #isSatisfied(Population)} returns true. |
| * |
| * @since 2.0 |
| */ |
| public class FixedGenerationCount implements StoppingCondition { |
| /** Number of generations that have passed */ |
| private int numGenerations = 0; |
| |
| /** Maximum number of generations (stopping criteria) */ |
| private final int maxGenerations; |
| |
| /** |
| * Create a new FixedGenerationCount instance. |
| * |
| * @param maxGenerations number of generations to evolve |
| * @throws NumberIsTooSmallException if the number of generations is < 1 |
| */ |
| public FixedGenerationCount(final int maxGenerations) throws NumberIsTooSmallException { |
| if (maxGenerations <= 0) { |
| throw new NumberIsTooSmallException(maxGenerations, 1, true); |
| } |
| this.maxGenerations = maxGenerations; |
| } |
| |
| /** |
| * Determine whether or not the given number of generations have passed. Increments the number of generations |
| * counter if the maximum has not been reached. |
| * |
| * @param population ignored (no impact on result) |
| * @return <code>true</code> IFF the maximum number of generations has been exceeded |
| */ |
| @Override |
| public boolean isSatisfied(final Population population) { |
| if (this.numGenerations < this.maxGenerations) { |
| numGenerations++; |
| return false; |
| } |
| return true; |
| } |
| |
| /** |
| * Returns the number of generations that have already passed. |
| * @return the number of generations that have passed |
| */ |
| public int getNumGenerations() { |
| return numGenerations; |
| } |
| |
| } |