001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.math3.genetics;
018
019import org.apache.commons.math3.exception.NumberIsTooLargeException;
020
021
022/**
023 * A collection of chromosomes that facilitates generational evolution.
024 *
025 * @since 2.0
026 * @version $Id: Population.java 1416643 2012-12-03 19:37:14Z tn $
027 */
028public interface Population extends Iterable<Chromosome> {
029    /**
030     * Access the current population size.
031     * @return the current population size.
032     */
033    int getPopulationSize();
034
035    /**
036     * Access the maximum population size.
037     * @return the maximum population size.
038     */
039    int getPopulationLimit();
040
041    /**
042     * Start the population for the next generation.
043     * @return the beginnings of the next generation.
044     */
045    Population nextGeneration();
046
047    /**
048     * Add the given chromosome to the population.
049     * @param chromosome the chromosome to add.
050     * @throws NumberIsTooLargeException if the population would exceed the population limit when adding
051     *   this chromosome
052     */
053    void addChromosome(Chromosome chromosome) throws NumberIsTooLargeException;
054
055    /**
056     * Access the fittest chromosome in this population.
057     * @return the fittest chromosome.
058     */
059    Chromosome getFittestChromosome();
060}