ga/src/gas/laralga.cpp

/********************************************************************************
 *  FARSA Genetic Algorithm Library                                             *
 *  Copyright (C) 2007-2008 Gianluca Massera <emmegian@yahoo.it>                *
 *                                                                              *
 *  This program is free software; you can redistribute it and/or modify        *
 *  it under the terms of the GNU General Public License as published by        *
 *  the Free Software Foundation; either version 2 of the License, or           *
 *  (at your option) any later version.                                         *
 *                                                                              *
 *  This program is distributed in the hope that it will be useful,             *
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of              *
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               *
 *  GNU General Public License for more details.                                *
 *                                                                              *
 *  You should have received a copy of the GNU General Public License           *
 *  along with this program; if not, write to the Free Software                 *
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA  *
 ********************************************************************************/

#include "gas/laralga.h"
#include "core/mutation.h"
#include "core/genome.h"
#include "evaluations/multitrials.h"
#include "factory.h"
#include <QThreadPool>
#include <QtConcurrentMap>
using namespace QtConcurrent;

namespace farsa {

LaralGA::LaralGA()
    : GeneticAlgo() {
    fitfunc = 0;
    muta = 0;
    currGenotype = 0;
    numGens = 0;
    nreproducing = 0;
    noffspring = 0;
    nelitism = 0;
    elitismEnabled = 0;
    currPhase = initEvaluation;
    numThreadv = 1;
    isInitialized = false;
    isFinalized = true;
}

LaralGA::~LaralGA() {
    //--- nothing to do
}

void LaralGA::configure( ConfigurationParameters& params, QString prefix ) {
    setGenome( params.getObjectFromGroup<Genome>( prefix + QString( "GENOME" ) ) );
    setFitnessFunction( params.getObjectFromGroup<MultiTrials>( prefix + QString( "EVALUATION" ) ) );
    fitfunc->setGenome( genome() );
    setMutation( params.getObjectFromGroup<Mutation>( prefix + QString("REPRODUCTION/MUTATION") ) );
    setNumGenerations( params.getValue( prefix + QString( "ngenerations" ) ).toInt() );
    if ( numGenerations() == 0 ) {
        qWarning( "Setting number of Generations to ZERO!! Check your config file" );
    }
    const QString reproductionGroup( prefix + QString( "REPRODUCTION" ) + ConfigurationParameters::GroupSeparator() );
    int nreproduce = params.getValue( reproductionGroup + QString( "nreproducing" ) ).toInt();
    bool useElitism = ! (params.getValue( reproductionGroup + QString( "elitism" ) ).compare( "true", Qt::CaseInsensitive));
    int nelitism = params.getValue( reproductionGroup + QString( "nelited" ) ).toInt();
    setReproduceParams( nreproduce, useElitism, nelitism );
    setNumThreads( params.getValue( prefix + QString( "numThreads" ) ).toInt() );
}

void LaralGA::save( ConfigurationParameters& params, QString prefix ) {
    params.createParameter( prefix, QString("type"), "LaralGA" );
    params.createParameter( prefix, QString("numThreads"), QString("%1").arg(numThreads()) );
    params.createParameter( prefix, QString("ngenerations"), QString("%1").arg( numGenerations() ) );
    //--- EVALUATION
    fitnessFunction()->save( params, params.createSubGroup( prefix, "EVALUATION" ) );
    //--- REPRODUCTION
    QString reproductionGroup = params.createSubGroup( prefix, "REPRODUCTION" );
    params.createParameter( reproductionGroup, "nreproducing", QString("%1").arg( numReproducing() ) );
    params.createParameter( reproductionGroup, "elitism", isElitismEnabled() ? "true" : "false" );
    params.createParameter( reproductionGroup, "nelited", QString("%1").arg( numElitism() ) );
    mutation()->save( params, params.createSubGroup( reproductionGroup, "MUTATION" ) );
    //--- GENOME
    genome()->save( params, params.createSubGroup( prefix, "GENOME" ) );
}

void LaralGA::describe( QString type ) {
    Descriptor d = addTypeDescription( type, "A simple Genetic Algorithm used at LARAL laboratory", "This Genetic Algorithm runs more than one replica of the evolutionary process each of them use a reproduction schema without crossover and with a deterministic rank selection" );
    d.describeInt( "numThreads" ).limits( 1, 32 ).help( "Number of threads to parallelize the evaluation of individuals" );
    d.describeInt( "ngenerations" ).limits( 1, INT_MAX ).props( IsMandatory ).help( "Number of generations per evolutionary process" );
    d.describeSubgroup( "EVALUATION" ).type( "MultiTrials" ).props( IsMandatory ).help( "Object that calculate the fitness", "Create a subclass of MultiTrials and code your custom fitness function" );
    SubgroupDescriptor r = d.describeSubgroup( "REPRODUCTION" ).props( IsMandatory ).help( "Paramenters that affect the reproduction process" );
        r.describeInt( "nreproducing" ).limits( 1, INT_MAX ).def(10).props( IsMandatory ).help( "Number of the most fitted individual to reproduce" );
        r.describeBool( "elitism" ).def( false ).help( "Enable the elitism", "When true, the nelited most fitted individual will be copied exactly (without mutation) to the new generations" );
        r.describeInt( "nelited" ).limits( 1, INT_MAX ).def( 10 ).help( "Number of individual to copy exactly to the new generation" );
        r.describeSubgroup( "MUTATION" ).type( "Mutation" ).props( IsMandatory ).help( "The type of mutation to use" );
    d.describeSubgroup( "GENOME" ).type( "Genome" ).props( IsMandatory ).help( "The genome containing the individual under evolution" );
}

void LaralGA::setNumThreads( int numThreads ) {
    if ( numThreads < 1 ) {
        qWarning( "The number of Threads must be greater than one!!" );
    }
    Q_ASSERT_X( !isInitialized && isFinalized ,
            "LaralGA::setNumThreads",
            "This method can only called before initialize of LaralGA" );
    Q_ASSERT_X( fitfunc != 0 ,
            "LaralGA::setNumThreads",
            "This method must be called after a MultiTrials object has been setted by LaralGA::setFitnessFunction" );
    numThreadv = numThreads;
    return;
}

int LaralGA::numThreads() {
    return numThreadv;
}

void LaralGA::setFitnessFunction( MultiTrials* fitfunc ) {
    this->fitfunc = fitfunc;
    this->fitfunc->setGA( this );
}

Evaluation* LaralGA::evaluationPrototype()
{
    return fitfunc;
}

QVector<Evaluation*> LaralGA::evaluationPool() {
    QVector<Evaluation*> ev;
    foreach( LaralGA::evaluationThread* e, evalThreads ) {
        ev.append( e->eval );
    }
    return ev;
}

MultiTrials* LaralGA::fitnessFunction() {
    return fitfunc;
}

void LaralGA::setMutation( Mutation* mutate ) {
    this->muta = mutate;
    this->muta->setGA( this );
}

Mutation* LaralGA::mutation() {
    return muta;
}

void LaralGA::setReproduceParams( int nreproducing, bool useElitism, int nelitism ) {
    this->nreproducing = nreproducing;
    elitismEnabled = useElitism;
    this->nelitism = nelitism;
    noffspring = genomev->size()/nreproducing;
    //--- check if parameters are setted correctly
    Q_ASSERT_X( noffspring * nreproducing == (int)(genomev->size()),
                "LaralGA::setReproduceParams",
                QString( "nreproducing must be divisible by genome dimension: %1 %2 %3" ).arg(noffspring).arg(nreproducing).arg(genomev->size()).toAscii().data() );
    if ( useElitism ) {
        Q_ASSERT_X( useElitism && ( nelitism <= nreproducing ),
                "LaralGA::setReproduceParams",
                "The number of elited genotype must be less or equal to selected ones" );
    }
}

int LaralGA::numReproducing() {
    return nreproducing;
}

int LaralGA::numOffspring() {
    return noffspring;
}

int LaralGA::numElitism() {
    return nelitism;
}

bool LaralGA::isElitismEnabled() {
    return elitismEnabled;
}

void LaralGA::initialize() {
    if ( isInitialized && !isFinalized ) return;
    Q_ASSERT_X( fitfunc != 0 ,
            "LaralGA::initialize",
            "You have to setup the FitnessFunction of LaralGA" );
    Q_ASSERT_X( muta !=0 ,
            "LaralGA::initialize",
            "You have to setup the Mutate operator of LaralGA" );

    isInitialized = true;
    isFinalized = false;
    currGenotype = 0;
    setGeneration( 0 );
    currPhase = initEvaluation;
    evolutionEnd = false;
    evaluationDone = false;
    //--- Setting up the evalThreads
    for( int i=0; i<evalThreads.size(); i++ ) {
        delete (evalThreads[i]);
    }
    evalThreads.clear();
    for( int i=0; i<numThreadv; i++ ) {
        evalThreads.append( new evaluationThread( this, fitfunc ) );
    }
    //--- set the number of thread to create
    QThreadPool::globalInstance()->setMaxThreadCount( numThreadv );
}

void LaralGA::gaStep() {
    switch( currPhase ) {
    case initEvaluation:
        for( int i=0; i<numThreadv; i++ ) {
            evalThreads[i]->sequence.clear();
        }
        for( int i=0; i<(int)genome()->size(); i++ ) {
            evalThreads[ i%numThreadv ]->sequence.append( i );
        }
        for( int i=0; i<numThreadv; i++ ) {
            evalThreads[i]->idSeq = 0;
            evalThreads[i]->id = evalThreads[i]->sequence[ evalThreads[i]->idSeq ];
            evalThreads[i]->eval->setGenome( genome() );
            evalThreads[i]->eval->initialize( genome()->at( evalThreads[i]->id ) );
            evalThreads[i]->blocked = false;
        }
        currPhase = evaluating;
        break;
    case evaluating: { /* Multi Thread Block (i.e. Parallel Evaluation of Genotypes */
        nextGeneration = true;
        if ( numThreadv == 1 ) {
            // Don't use Threads if is not necessary
            evalThreads[0]->runStep();
        } else {
            QFuture<void> future = map( evalThreads, LaralGA::runStepWrapper );
            future.waitForFinished();
        }
        if ( nextGeneration ) {
            currPhase = nextGeneration_pass1;
        }
        } /* End of Multi Thread Block */
        break;
    case nextGeneration_pass1:
        qSort( genome()->begin(), genome()->end(), Genotype::rankGreaterThanComparator );
        updateStats();
        evaluationDone = true;
        if ( generation() < numGens ) {
            currPhase = nextGeneration_pass2;
        } else {
            currPhase = endEvolution;
        }
        break;
    case nextGeneration_pass2:
        //--- this additional pass is for avoid to modify the
        //--- genotypes contained in the last generation of the evolution
        //--- and to allow to save the genotypes after each generation
        setGeneration( generation()+1 );
        evaluationDone = false;
        createNextGeneration();
        currPhase = initEvaluation;
        break;
    case endEvolution:
        finalize();
        qWarning( "Finish Evolution" );
        break;
    default:
        qFatal( "Default switch in LaralGA::gaStep" );
        break;
    }
}

void LaralGA::skipEvaluation() {
    // Set evaluation done, and check which phase to go to
    evaluationDone = true;
    if ( generation() < numGens ) {
        currPhase = nextGeneration_pass2;
    } else {
        currPhase = endEvolution;
    }
}

void LaralGA::finalize() {
    if ( isFinalized && !isInitialized ) return;

    isInitialized = false;
    isFinalized = true;
    evolutionEnd = true;
}

void LaralGA::createNextGeneration() {
    Genome& genref = *(genome());
    muta->setGenome( genome() );
    for( int i=0; i<nreproducing; i++ ) {
        //--- skip for now the first nreproducing position
        for( int j=1; j<noffspring; j++ ) {
            //--- id of the current genome to replace
            int id = i + j*nreproducing;
            //--- clone and mutate the i-th selected individual
            genref[id]->assign( genref[i] );
            muta->mutate( genref[id] );
        }
    }
    //--- also mutate the selected, excepted for the elited ones
    int startId = 0;
    if ( elitismEnabled ) {
        startId = nelitism;
    }
    for( int i=startId; i<nreproducing; i++ ) {
        muta->mutate( genref[i] );
    }
}

LaralGA::evaluationThread::evaluationThread( LaralGA* p, MultiTrials* eProto )
    : parent(p), id(0), blocked(false) {
    eval = eProto->clone();
    eval->setGenome( p->genome() );
    eval->setGA( p );
}

LaralGA::evaluationThread::~evaluationThread() {
    delete eval;
    sequence.clear();
}

void LaralGA::evaluationThread::runStep() {
    if ( blocked ) {
        return;
    }
    
    parent->nextGeneration = false;
    eval->evaluateStep();
    if ( eval->isEvaluationDone() ) {
        int nextIdSeq = idSeq + 1;
        eval->finalize();
        eval->genotype()->setRank( eval->genotype()->fitness() );
        if ( nextIdSeq >= sequence.size() ) {
            blocked = true;
            return;
        }
        idSeq = nextIdSeq;
        int nextId = sequence[ idSeq ];
        id = nextId;
        eval->initialize( parent->genome()->at( id ) );
    }
}

void LaralGA::runStepWrapper( LaralGA::evaluationThread* e ) {
    e->runStep();
}

} // end namespace farsa