/*
* 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.math3.genetics;
import org.apache.commons.math3.exception.NumberIsTooSmallException;
Stops after a fixed number of generations. Each time isSatisfied(Population)
is invoked, a generation counter is incremented. Once the counter reaches the configured maxGenerations
value, isSatisfied(Population)
returns true. Since: 2.0
/**
* Stops after a fixed number of generations. Each time {@link #isSatisfied(Population)} is invoked, a generation
* counter is incremented. Once the counter reaches the configured <code>maxGenerations</code> value,
* {@link #isSatisfied(Population)} returns true.
*
* @since 2.0
*/
public class FixedGenerationCount implements StoppingCondition {
Number of generations that have passed /** Number of generations that have passed */
private int numGenerations = 0;
Maximum number of generations (stopping criteria) /** Maximum number of generations (stopping criteria) */
private final int maxGenerations;
Create a new FixedGenerationCount instance.
Params: - maxGenerations – number of generations to evolve
Throws: - NumberIsTooSmallException – if the number of generations is < 1
/**
* 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.
Params: - population – ignored (no impact on result)
Returns: true
IFF the maximum number of generations has been exceeded
/**
* 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
*/
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.
Returns: the number of generations that have passed
/**
* Returns the number of generations that have already passed.
* @return the number of generations that have passed
*/
public int getNumGenerations() {
return numGenerations;
}
}