FixedGenerationCount.java
- /*
- * 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.legacy.genetics;
- import org.apache.commons.math4.legacy.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;
- /** 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;
- }
- }