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     */
017    package org.apache.commons.math3.genetics;
018    
019    import 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     */
028    public 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    }