LauSimFitMaster.cc

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// Copyright University of Warwick 2013 - 2013.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

// Authors:
// Thomas Latham
// John Back
// Paul Harrison

#include <cstdlib>
#include <iostream>

#include "TMessage.h"
#include "TMonitor.h"
#include "TObjArray.h"
#include "TObjString.h"
#include "TServerSocket.h"
#include "TSocket.h"
#include "TSystem.h"
#include "TVectorD.h"

#include "LauAbsFitter.hh"
#include "LauFitNtuple.hh"
#include "LauFitter.hh"
#include "LauParameter.hh"
#include "LauParamFixed.hh"
#include "LauSimFitMaster.hh"


ClassImp(LauSimFitMaster)


LauSimFitMaster::LauSimFitMaster( UInt_t numSlaves, UInt_t port ) :
        nSlaves_(numSlaves),
        reqPort_(port),
        nParams_(0),
        nFreeParams_(0),
        withinAsymErrorCalc_(kFALSE),
        numberOKFits_(0),
        numberBadFits_(0),
        fitStatus_(0),
        iExpt_(0),
        NLL_(0.0),
        socketMonitor_(0),
        messageFromSlave_(0),
        fitNtuple_(0)
{
        messagesToSlaves_.resize( nSlaves_ );
        for ( UInt_t iSlave(0); iSlave < nSlaves_; ++iSlave ) {
                messagesToSlaves_[iSlave] = new TMessage();
        }
}

LauSimFitMaster::~LauSimFitMaster()
{
        delete socketMonitor_; socketMonitor_ = 0;
        TString msgStr("Finish");
        TMessage message( kMESS_STRING );
        message.WriteTString(msgStr);
        for ( std::vector<TSocket*>::iterator iter = sSlaves_.begin(); iter != sSlaves_.end(); ++iter ) {
                (*iter)->Send(message);
                (*iter)->Close();
                delete (*iter);
        }
        sSlaves_.clear();
        for ( std::vector<LauParameter*>::iterator iter = params_.begin(); iter != params_.end(); ++iter ) {
                delete *iter;
        }
        params_.clear();
        for ( std::vector<Double_t*>::iterator iter = vectorPar_.begin(); iter != vectorPar_.end(); ++iter ) {
                delete[] (*iter);
        }
        vectorPar_.clear();
        delete messageFromSlave_; messageFromSlave_ = 0;
        for ( std::vector<TMessage*>::iterator iter = messagesToSlaves_.begin(); iter != messagesToSlaves_.end(); ++iter ) {
                delete (*iter);
        }
        messagesToSlaves_.clear();
        delete fitNtuple_;
}

void LauSimFitMaster::initSockets()
{
        if ( socketMonitor_ != 0 ) {
                std::cerr << "ERROR in LauSimFitMaster::initSockets : Sockets already initialised." << std::endl;
                return;
        }

        //initialise socket connection, then accept a connection and return a full-duplex communication socket.
        socketMonitor_ = new TMonitor();

        TServerSocket *ss = new TServerSocket( reqPort_, kFALSE );
        UInt_t actual_port = ss->GetLocalPort();

        std::cout << "INFO in LauSimFitMaster::initSockets : Waiting for connection with " << nSlaves_ << " workers on port " << actual_port << std::endl;

        sSlaves_.resize(nSlaves_);
        for ( UInt_t iSlave(0); iSlave<nSlaves_; ++iSlave ) {
                sSlaves_[iSlave] = ss->Accept();
                std::cout << "                                     : Added slave " << iSlave << std::endl;
        }

        // tell the clients to start
        std::cout << "INFO in LauSimFitMaster::initSockets : Initialising slaves" << std::endl;
        for ( UInt_t iSlave(0); iSlave<nSlaves_; ++iSlave ) {

                TMessage message( kMESS_ANY );
                message.WriteUInt(iSlave);
                message.WriteUInt(nSlaves_);

                sSlaves_[iSlave]->Send(message);

                socketMonitor_->Add(sSlaves_[iSlave]);
        }
        std::cout << "                                     : Now start fit\n" << std::endl;

        ss->Close();
        delete ss;
}

/*
 * OLD VERSION THAT JUST GETS THE NAMES - COULD HAVE A SERIES OF EXCHANGES TO GET THE NAMES, INIT VALUES, RANGES, ETC. INSTEAD OF PASSING PARAMETERS
 * THIS INCREASES THE GENERALITY OF THE CODE, I.E. THERE IS NO NEED FOR THE SLAVES TO KNOW ANY LAURA++ CLASS BUT THIS ONE, BUT MAKES IT RATHER MORE DENSE
 * FOR THE MOMENT I WILL STICK WITH THE METHOD OF PASSING LAUPARAMETER OBJECTS AROUND AND CONSIDER GOING BACK TO THIS GENERAL METHOD ONCE EVERYTHING IS WORKING
 *
void LauSimFitMaster::getParametersFromSlavesFirstTime()
{
        slaveIndices_.resize( nSlaves_ );

        TSocket* sActive(0);
        for ( UInt_t iSlave(0); iSlave<nSlaves_; ++iSlave ) {
                // Send a message to the slave, requesting the list of parameter names
                TString msgStr = "Parameter Names";
                TMessage message( kMESS_STRING );
                message.WriteTString( msgStr );
                sSlaves_[iSlave]->Send(message);

                // Wait to receive the response and check that it has come from the slave we just requested from
                sActive = socketMonitor_->Select();
                if ( sActive != sSlaves_[iSlave] ) {
                        std::cerr << "ERROR in LauSimFitMaster::getParametersFromSlavesFirstTime : Received message from a different slave than expected!" << std::endl;
                        gSystem->Exit(1);
                }

                // Read the object and extract the parameter names
                sSlaves_[iSlave]->Recv( messageFromSlave_ );
                TObjArray * objarray = dynamic_cast<TObjArray*>( messageFromSlave_->ReadObject( messageFromSlave_->GetClass() ) );
                if ( ! objarray ) {
                        std::cerr << "ERROR in LauSimFitMaster::getParametersFromSlavesFirstTime : Error reading parameter names from slave" << std::endl;
                        gSystem->Exit(1);
                }

                Int_t nPars = objarray->GetEntries();
                for ( Int_t iPar(0); iPar < nPars; ++iPar ) {
                        TObjString* objstring = dynamic_cast<TObjString*>( (*objarray)[iPar] );
                        if ( ! objstring ) {
                                std::cerr << "ERROR in LauSimFitMaster::getParametersFromSlavesFirstTime : Error reading parameter names from slave" << std::endl;
                                gSystem->Exit(1);
                        }
                        TString parname = objstring->GetString();

                        std::map< TString, UInt_t >::iterator iter = parIndices_.find( parname );
                        if ( iter != parIndices_.end() ) {
                                UInt_t index = iter->second;
                                slaveIndices_[iSlave].push_back( index );
                        } else {
                                UInt_t index = parIndices_.size();
                                parIndices_.insert( std::make_pair( parname, index ) );
                                parNames_.insert( std::make_pair( index, parname ) );
                                slaveIndices_[iSlave].push_back( index );
                        }
                }

                delete objarray; objarray = 0;
                delete messageFromSlave_; messageFromSlave_ = 0;
        }

        UInt_t nPars = parNames_.size();
        parValues_.resize( nPars );
}
*/

void LauSimFitMaster::getParametersFromSlaves()
{
        if ( socketMonitor_ == 0 ) {
                std::cerr << "ERROR in LauSimFitMaster::getParametersFromSlaves : Sockets not initialised." << std::endl;
                return;
        }

        if ( params_.empty() ) {
                this->getParametersFromSlavesFirstTime();
        } else {
                this->updateParametersFromSlaves();
        }
}

void LauSimFitMaster::updateParametersFromSlaves()
{
        TSocket* sActive(0);

        // Construct a message, requesting the list of parameter names
        TString msgStr = "Send Parameters";
        TMessage message( kMESS_STRING );
        message.WriteTString( msgStr );

        for ( UInt_t iSlave(0); iSlave<nSlaves_; ++iSlave ) {
                // Send the message to the slave
                sSlaves_[iSlave]->Send(message);

                // Wait to receive the response and check that it has come from the slave we just requested from
                sActive = socketMonitor_->Select();
                if ( sActive != sSlaves_[iSlave] ) {
                        std::cerr << "ERROR in LauSimFitMaster::updateParametersFromSlaves : Received message from a different slave than expected!" << std::endl;
                        gSystem->Exit(1);
                }

                // Read the object and extract the parameter names
                sSlaves_[iSlave]->Recv( messageFromSlave_ );
                TObjArray * objarray = dynamic_cast<TObjArray*>( messageFromSlave_->ReadObject( messageFromSlave_->GetClass() ) );
                if ( ! objarray ) {
                        std::cerr << "ERROR in LauSimFitMaster::updateParametersFromSlaves : Error reading parameter names from slave" << std::endl;
                        gSystem->Exit(1);
                }

                // We want to auto-delete the supplied parameters since we only copy their values in this case
                objarray->SetOwner(kTRUE);

                const UInt_t nPars = objarray->GetEntries();
                if ( nPars != slaveIndices_[iSlave].size() ) {
                        std::cerr << "ERROR in LauSimFitMaster::updateParametersFromSlaves : Unexpected number of parameters received from slave" << std::endl;
                        gSystem->Exit(1);
                }

                for ( UInt_t iPar(0); iPar < nPars; ++iPar ) {
                        LauParameter* parameter = dynamic_cast<LauParameter*>( (*objarray)[iPar] );
                        if ( ! parameter ) {
                                std::cerr << "ERROR in LauSimFitMaster::updateParametersFromSlaves : Error reading parameter from slave" << std::endl;
                                gSystem->Exit(1);
                        }

                        TString parname = parameter->name();
                        Double_t parvalue = parameter->initValue();

                        std::map< TString, UInt_t >::iterator iter = parIndices_.find( parname );
                        if ( iter == parIndices_.end() ) {
                                std::cerr << "ERROR in LauSimFitMaster::updateParametersFromSlaves : Unexpected parameter name received from slave" << std::endl;
                                gSystem->Exit(1);
                        }

                        const UInt_t index = iter->second;
                        if ( slaveIndices_[iSlave][iPar] != index ) {
                                std::cerr << "ERROR in LauSimFitMaster::updateParametersFromSlaves : Unexpected parameter received from slave" << std::endl;
                                gSystem->Exit(1);
                        }

                        params_[index]->initValue( parvalue );
                        parValues_[index] = parvalue;
                        vectorPar_[iSlave][iPar] = parvalue;
                        this->checkParameter( parameter, index );
                }

                delete objarray; objarray = 0;
                delete messageFromSlave_; messageFromSlave_ = 0;
        }
}

void LauSimFitMaster::getParametersFromSlavesFirstTime()
{
        slaveIndices_.resize( nSlaves_ );
        vectorPar_.resize( nSlaves_ );
        vectorRes_.resize( nSlaves_ );

        TSocket* sActive(0);

        // Construct a message, requesting the list of parameter names
        TString msgStr = "Send Parameters";
        TMessage message( kMESS_STRING );
        message.WriteTString( msgStr );

        for ( UInt_t iSlave(0); iSlave<nSlaves_; ++iSlave ) {
                // Send the message to the slave
                sSlaves_[iSlave]->Send(message);

                // Wait to receive the response and check that it has come from the slave we just requested from
                sActive = socketMonitor_->Select();
                if ( sActive != sSlaves_[iSlave] ) {
                        std::cerr << "ERROR in LauSimFitMaster::getParametersFromSlavesFirstTime : Received message from a different slave than expected!" << std::endl;
                        gSystem->Exit(1);
                }

                // Read the object and extract the parameter names
                sSlaves_[iSlave]->Recv( messageFromSlave_ );
                TObjArray * objarray = dynamic_cast<TObjArray*>( messageFromSlave_->ReadObject( messageFromSlave_->GetClass() ) );
                if ( ! objarray ) {
                        std::cerr << "ERROR in LauSimFitMaster::getParametersFromSlavesFirstTime : Error reading parameters from slave" << std::endl;
                        gSystem->Exit(1);
                }

                const UInt_t nPars = objarray->GetEntries();

                vectorPar_[iSlave] = new Double_t[nPars];

                for ( UInt_t iPar(0); iPar < nPars; ++iPar ) {
                        LauParameter* parameter = dynamic_cast<LauParameter*>( (*objarray)[iPar] );
                        if ( ! parameter ) {
                                std::cerr << "ERROR in LauSimFitMaster::getParametersFromSlavesFirstTime : Error reading parameter from slave" << std::endl;
                                gSystem->Exit(1);
                        }

                        TString parname = parameter->name();
                        Double_t parvalue = parameter->initValue();

                        std::map< TString, UInt_t >::iterator iter = parIndices_.find( parname );
                        if ( iter != parIndices_.end() ) {
                                UInt_t index = iter->second;
                                slaveIndices_[iSlave].push_back( index );
                                this->checkParameter( parameter, index );
                        } else {
                                UInt_t index = parIndices_.size();
                                parIndices_.insert( std::make_pair( parname, index ) );
                                parNames_.insert( std::make_pair( index, parname ) );
                                slaveIndices_[iSlave].push_back( index );
                                params_.push_back( parameter );
                                parValues_.push_back( parvalue );
                        }
                        vectorPar_[iSlave][iPar] = parvalue;
                }

                delete objarray; objarray = 0;
                delete messageFromSlave_; messageFromSlave_ = 0;
        }

        nParams_ = params_.size();
}

void LauSimFitMaster::printParInfo() const
{
        for ( UInt_t iSlave(0); iSlave<nSlaves_; ++iSlave ) {
                const std::vector<UInt_t>& indices = slaveIndices_[iSlave];

                std::cout << "INFO in LauSimFitMaster::printParInfo : Slave " << iSlave << " has the following parameters:\n";
                for ( std::vector<UInt_t>::const_iterator iter = indices.begin(); iter != indices.end(); ++iter ) {
                        const TString& parName = parNames_.find(*iter)->second;
                        Double_t parValue = parValues_[*iter];
                        const LauParameter* par = params_[*iter];
                        if ( par->name() != parName || par->initValue() != parValue ) {
                                std::cerr << "ERROR in LauSimFitMaster::printParInfo : Discrepancy in parameter name and value records, this is very strange!!" << std::endl;
                        }

                        std::cout << "                                      : " << parName << " = " << parValue << " and has index " << *iter << "\n";
                }

                std::cout << std::endl;
        }

        std::cout << "INFO in LauSimFitMaster::printParInfo : " << "There are " << nParams_ << " parameters in total" << std::endl;
}

void LauSimFitMaster::checkParameter( const LauParameter* param, UInt_t index ) const
{
        const LauParameter* storedPar = params_[index];

        TString parName = storedPar->name();
        if ( param->name() != parName ) {
                std::cerr << "ERROR in LauSimFitMaster::checkParameter : Parameter name is different!!  This shouldn't happen!!" << std::endl;
        }
        if ( param->initValue() != storedPar->initValue() ) {
                std::cerr << "WARNING in LauSimFitMaster::checkParameter : Initial value for parameter " << parName << " is different, will use the value first set: " << storedPar->initValue() << std::endl;
        }
        if ( param->minValue() != storedPar->minValue() ) {
                std::cerr << "WARNING in LauSimFitMaster::checkParameter : Minimum allowed value for parameter " << parName << " is different, will use the value first set: " << storedPar->minValue() << std::endl;
        }
        if ( param->maxValue() != storedPar->maxValue() ) {
                std::cerr << "WARNING in LauSimFitMaster::checkParameter : Maximum allowed value for parameter " << parName << " is different, will use the value first set: " << storedPar->maxValue() << std::endl;
        }
        if ( param->fixed() != storedPar->fixed() ) {
                std::cerr << "WARNING in LauSimFitMaster::checkParameter : Fixed/floating property of parameter " << parName << " is different, will use the value first set: " << (storedPar->fixed() ? "fixed" : "floating") << std::endl;
        }
        if ( param->firstStage() != storedPar->firstStage() ) {
                std::cerr << "WARNING in LauSimFitMaster::checkParameter : First stage property of parameter " << parName << " is different, will use the value first set: " << (storedPar->firstStage() ? "true" : "false") << std::endl;
        }
        if ( param->secondStage() != storedPar->secondStage() ) {
                std::cerr << "WARNING in LauSimFitMaster::checkParameter : Second stage property of parameter " << parName << " is different, will use the value first set: " << (storedPar->secondStage() ? "true" : "false") << std::endl;
        }
}

void LauSimFitMaster::initialise()
{
        this->initSockets();
}

void LauSimFitMaster::runSimFit( const TString& fitNtupleFileName, UInt_t nExpt, UInt_t firstExpt, Bool_t useAsymmErrors, Bool_t twoStageFit )
{
        // Routine to perform the total fit.

        // First, initialise
        this->initialise();

        std::cout << "INFO in LauSimFitMaster::runSimFit : First experiment = " << firstExpt << std::endl;
        std::cout << "INFO in LauSimFitMaster::runSimFit : Number of experiments = " << nExpt << std::endl;

        // Start the cumulative timer
        cumulTimer_.Start();

        numberOKFits_ = 0, numberBadFits_ = 0;
        fitStatus_ = -1;

        // Create and setup the fit results ntuple
        std::cout << "INFO in LauSimFitMaster::runSimFit : Creating fit ntuple." << std::endl;
        if (fitNtuple_ != 0) {delete fitNtuple_; fitNtuple_ = 0;}
        fitNtuple_ = new LauFitNtuple(fitNtupleFileName, useAsymmErrors);

        // Loop over the number of experiments
        for (iExpt_ = firstExpt; iExpt_ < (firstExpt+nExpt); ++iExpt_) {

                // Start the timer to see how long each fit takes
                timer_.Start();

                // Instruct the slaves to read the data for this experiment
                Bool_t readOK = this->readData();
                if ( ! readOK ) {
                        std::cerr << "ERROR in LauSimFitMaster::runSimFit : One or more slaves reported problems with reading data for experiment " << iExpt_ << ", skipping..." << std::endl;
                        timer_.Stop();
                        continue;
                }

                // Instruct the slaves to perform the caching
                this->cacheInputData();

                // Do the fit
                this->fitExpt( useAsymmErrors, twoStageFit );

                // Stop the timer and see how long the program took so far
                timer_.Stop();
                timer_.Print();

                // Instruct the slaves to finalise the results
                this->finalise();

                // Keep track of how many fits succeeded or failed
                if (fitStatus_ == 3) {
                        ++numberOKFits_;
                } else {
                        ++numberBadFits_;
                }
        }

        // Print out total timing info.
        std::cout << "INFO in LauSimFitMaster::runSimFit : Cumulative timing:" << std::endl;
        cumulTimer_.Stop();
        cumulTimer_.Print();

        // Print out stats on OK fits.
        std::cout << "INFO in LauSimFitMaster::runSimFit : Number of OK Fits = " << numberOKFits_ << std::endl;
        std::cout << "INFO in LauSimFitMaster::runSimFit : Number of Failed Fits = " << numberBadFits_ << std::endl;
        Double_t fitEff(0.0);
        if (nExpt != 0) {fitEff = numberOKFits_/(1.0*nExpt);}
        std::cout << "INFO in LauSimFitMaster::runSimFit : Fit efficiency = " << fitEff*100.0 << "%." << std::endl;

        // Instruct the slaves to write out any fit results (ntuples etc...).
        this->writeOutResults();
}

Bool_t LauSimFitMaster::readData()
{
        if ( socketMonitor_ == 0 ) {
                std::cerr << "ERROR in LauSimFitMaster::readData : Sockets not initialised." << std::endl;
                return kFALSE;
        }

        // Construct a message, requesting to read the data for the given experiment
        TString msgStr("Read Expt");
        TMessage message( kMESS_STRING );
        message.WriteTString( msgStr );
        message.WriteUInt( iExpt_ );

        // Send the message to the slaves
        for ( UInt_t iSlave(0); iSlave<nSlaves_; ++iSlave ) {
                sSlaves_[iSlave]->Send(message);
        }

        TSocket* sActive(0);
        UInt_t responsesReceived(0);
        Bool_t ok(kTRUE);
        while ( responsesReceived != nSlaves_ ) {

                // Get the next queued response
                sActive = socketMonitor_->Select();

                // Extract from the message the ID of the slave and the number of events read
                sActive->Recv( messageFromSlave_ );
                UInt_t iSlave(0);
                UInt_t nEvents(0);
                messageFromSlave_->ReadUInt( iSlave );
                messageFromSlave_->ReadUInt( nEvents );

                if ( nEvents <= 0 ) {
                        std::cerr << "ERROR in LauSimFitMaster::readData : Slave " << iSlave << " reports no events found for experiment " << iExpt_ << std::endl;
                        ok = kFALSE;
                } else {
                        std::cerr << "INFO in LauSimFitMaster::readData : Slave " << iSlave << " reports " << nEvents << " events found for experiment " << iExpt_ << std::endl;
                }

                ++responsesReceived;
        }

        return ok;
}

Bool_t LauSimFitMaster::cacheInputData()
{
        if ( socketMonitor_ == 0 ) {
                std::cerr << "ERROR in LauSimFitMaster::cacheInputData : Sockets not initialised." << std::endl;
                return kFALSE;
        }

        // Construct a message, requesting it to read the data for the given experiment
        TString msgStr("Cache");
        TMessage message( kMESS_STRING );
        message.WriteTString( msgStr );

        for ( UInt_t iSlave(0); iSlave<nSlaves_; ++iSlave ) {
                // Send the message to the slave
                sSlaves_[iSlave]->Send(message);
        }

        TSocket* sActive(0);
        UInt_t responsesReceived(0);
        Bool_t allOK(kTRUE);
        while ( responsesReceived != nSlaves_ ) {

                // Get the next queued response
                sActive = socketMonitor_->Select();

                // Extract from the message the ID of the slave and the success/failure flag
                sActive->Recv( messageFromSlave_ );
                UInt_t iSlave(0);
                Bool_t ok(kTRUE);
                messageFromSlave_->ReadUInt( iSlave );
                messageFromSlave_->ReadBool( ok );

                if ( ! ok ) {
                        std::cerr << "ERROR in LauSimFitMaster::cacheInputData : Slave " << iSlave << " reports an error performing caching" << std::endl;
                        allOK = kFALSE;
                }

                ++responsesReceived;
        }

        return allOK;
}

void LauSimFitMaster::checkInitFitParams()
{
        this->getParametersFromSlaves();
        this->printParInfo();
}

void LauSimFitMaster::fitExpt( Bool_t useAsymmErrors, Bool_t twoStageFit )
{
        // Routine to perform the actual fit for the given experiment

        // Instruct the salves to update initial fit parameters if required (e.g. if using random numbers).
        this->checkInitFitParams();

        // Initialise the fitter
        LauFitter::fitter()->useAsymmFitErrors( useAsymmErrors );
        LauFitter::fitter()->twoStageFit( twoStageFit );
        LauFitter::fitter()->initialise( this, params_ );

        nParams_ = LauFitter::fitter()->nParameters();
        nFreeParams_ = LauFitter::fitter()->nFreeParameters();

        // Now ready for minimisation step
        std::cout << "\nINFO in LauSimFitMaster::fitExpt : Start minimisation...\n";
        std::pair<Int_t,Double_t> fitResult = LauFitter::fitter()->minimise();

        fitStatus_ = fitResult.first;
        NLL_       = fitResult.second;

        // If we're doing a two stage fit we can now release (i.e. float)
        // the 2nd stage parameters and re-fit
        if ( twoStageFit ) {

                if ( fitStatus_ != 3 ) {
                        std::cerr << "ERROR in LauSimFitMaster:fitExpt : Not running second stage fit since first stage failed." << std::endl;
                        LauFitter::fitter()->releaseSecondStageParameters();
                } else {
                        LauFitter::fitter()->fixFirstStageParameters();
                        LauFitter::fitter()->releaseSecondStageParameters();
                        nParams_ = LauFitter::fitter()->nParameters();
                        nFreeParams_ = LauFitter::fitter()->nFreeParameters();
                        fitResult = LauFitter::fitter()->minimise();
                }
        }

        fitStatus_ = fitResult.first;
        NLL_       = fitResult.second;
        const TMatrixD& covMat = LauFitter::fitter()->covarianceMatrix();
        covMatrix_.Clear();
        covMatrix_.ResizeTo( covMat.GetNrows(), covMat.GetNcols() );
        covMatrix_.SetMatrixArray( covMat.GetMatrixArray() );

        // Store the final fit results and errors into protected internal vectors that
        // all sub-classes can use within their own finalFitResults implementation
        // used below (e.g. putting them into an ntuple in a root file)
        LauFitter::fitter()->updateParameters();
        LauFitter::fitter()->releaseFirstStageParameters();
}

void LauSimFitMaster::setParsFromMinuit(Double_t* par, Int_t npar)
{
        // This function sets the internal parameters based on the values
        // that Minuit is using when trying to minimise the total likelihood function.

        // MINOS reports different numbers of free parameters depending on the
        // situation, so disable this check
        if ( ! withinAsymErrorCalc_ ) {
                if (static_cast<UInt_t>(npar) != nFreeParams_) {
                        std::cerr << "ERROR in LauSimFitMaster::setParsFromMinuit : Unexpected number of free parameters: " << npar << ".\n";
                        std::cerr << "                                              Expected: " << nFreeParams_ << ".\n" << std::endl;
                        gSystem->Exit(EXIT_FAILURE);
                }
        }

        // Despite npar being the number of free parameters
        // the par array actually contains all the parameters,
        // free and floating...
        // Update all the parameters with their new values.
        for (UInt_t i(0); i<nParams_; ++i) {
                parValues_[i] = par[i];
        }
}

Double_t LauSimFitMaster::getTotNegLogLikelihood()
{
        if ( socketMonitor_ == 0 ) {
                std::cerr << "ERROR in LauSimFitMaster::getTotNegLogLikelihood : Sockets not initialised." << std::endl;
                return 0.0;
        }

        // Send current values of the parameters to the slaves.
        for ( UInt_t iSlave(0); iSlave<nSlaves_; ++iSlave ) {

                std::vector<UInt_t>& indices = slaveIndices_[iSlave];
                UInt_t nPars = indices.size();
                for ( UInt_t iPar(0); iPar < nPars; ++iPar ) {
                        vectorPar_[iSlave][iPar] = parValues_[ indices[iPar] ];
                }

                TMessage* message = messagesToSlaves_[iSlave];
                message->Reset( kMESS_ANY );
                message->WriteUInt( nPars );
                message->WriteFastArray( vectorPar_[iSlave], nPars );

                sSlaves_[iSlave]->Send(*message);
        }

        Double_t negLogLike(0.0);
        TSocket  *sActive(0);
        UInt_t responsesReceived(0);
        while ( responsesReceived != nSlaves_ ) {

                sActive = socketMonitor_->Select();
                sActive->Recv(messageFromSlave_);           

                messageFromSlave_->ReadDouble( vectorRes_[responsesReceived] );

                negLogLike += vectorRes_[responsesReceived];

                ++responsesReceived;
        } 

        return negLogLike;
}

Bool_t LauSimFitMaster::finalise()
{
        if ( socketMonitor_ == 0 ) {
                std::cerr << "ERROR in LauSimFitMaster::finalise : Sockets not initialised." << std::endl;
                return kFALSE;
        }

        // Prepare the covariance matrices
        covMatrices_.resize( nSlaves_ );

        LauParamFixed pred;

        std::map<UInt_t,UInt_t> freeParIndices;

        UInt_t counter(0);
        for ( UInt_t iPar(0); iPar < nParams_; ++iPar ) {
                const LauParameter* par = params_[iPar];
                if ( ! pred(par) ) {
                        freeParIndices.insert( std::make_pair(iPar,counter) );
                        ++counter;
                }
        }

        for ( UInt_t iSlave(0); iSlave<nSlaves_; ++iSlave ) {
                const UInt_t nPar = slaveIndices_[iSlave].size();

                std::vector<UInt_t> freeIndices;
                freeIndices.reserve( nPar );

                for ( UInt_t iPar(0); iPar < nPar; ++iPar ) {
                        UInt_t index = slaveIndices_[iSlave][iPar];
                        std::map<UInt_t,UInt_t>::iterator freeIter = freeParIndices.find(index);
                        if ( freeIter == freeParIndices.end() ) {
                                continue;
                        }
                        UInt_t freeIndex = freeIter->second;
                        freeIndices.push_back( freeIndex );
                }

                const UInt_t nFreePars = freeIndices.size();
                TMatrixD& covMat = covMatrices_[iSlave];
                covMat.ResizeTo( nFreePars, nFreePars );

                for ( UInt_t iPar(0); iPar < nFreePars; ++iPar ) {
                        for ( UInt_t jPar(0); jPar < nFreePars; ++jPar ) {
                                UInt_t i = freeIndices[iPar];
                                UInt_t j = freeIndices[jPar];
                                covMat( iPar, jPar ) = covMatrix_( i, j );
                        }
                }
        }

        // The array to hold the parameters
        TObjArray array;

        // Send messages to all slaves containing the final parameters and fit status, NLL
        // TODO - at present we lose the information on the correlations between the parameters that are unique to each slave
        //      - so should we store the full correlation matrix in an ntuple? along with all the parameters?
        for ( UInt_t iSlave(0); iSlave<nSlaves_; ++iSlave ) {

                array.Clear();

                std::vector<UInt_t>& indices = slaveIndices_[iSlave];
                UInt_t nPars = indices.size();
                for ( UInt_t iPar(0); iPar < nPars; ++iPar ) {
                        array.Add( params_[ indices[iPar] ] );
                }

                TMatrixD& covMat = covMatrices_[iSlave];

                TMessage* message = messagesToSlaves_[iSlave];
                message->Reset( kMESS_OBJECT );
                message->WriteInt( fitStatus_ );
                message->WriteDouble( NLL_ );
                message->WriteObject( &array );
                message->WriteObject( &covMat );

                sSlaves_[iSlave]->Send(*message);
        }

        TSocket  *sActive(0);
        UInt_t responsesReceived(0);
        Bool_t allOK(kTRUE);
        while ( responsesReceived != nSlaves_ ) {

                // Get the next queued response
                sActive = socketMonitor_->Select();

                // Extract from the message the ID of the slave and the number of events read
                sActive->Recv( messageFromSlave_ );
                UInt_t iSlave(0);
                Bool_t ok(kTRUE);
                messageFromSlave_->ReadUInt( iSlave );
                messageFromSlave_->ReadBool( ok );

                if ( ok ) {
                        TObjArray * objarray = dynamic_cast<TObjArray*>( messageFromSlave_->ReadObject( messageFromSlave_->GetClass() ) );
                        if ( ! objarray ) {
                                std::cerr << "ERROR in LauSimFitMaster::finalise : Error reading finalised parameters from slave" << std::endl;
                                allOK = kFALSE;
                        } else {
                                // We want to auto-delete the supplied parameters since we only copy their values in this case
                                objarray->SetOwner(kTRUE);

                                const UInt_t nPars = objarray->GetEntries();
                                if ( nPars != slaveIndices_[iSlave].size() ) {
                                        std::cerr << "ERROR in LauSimFitMaster::finalise : Unexpected number of finalised parameters received from slave" << std::endl;
                                        allOK = kFALSE;
                                } else {
                                        for ( UInt_t iPar(0); iPar < nPars; ++iPar ) {
                                                LauParameter* parameter = dynamic_cast<LauParameter*>( (*objarray)[iPar] );
                                                if ( ! parameter ) {
                                                        std::cerr << "ERROR in LauSimFitMaster::finalise : Error reading parameter from slave" << std::endl;
                                                        allOK = kFALSE;
                                                        continue;
                                                }

                                                TString parname = parameter->name();

                                                std::map< TString, UInt_t >::iterator iter = parIndices_.find( parname );
                                                if ( iter == parIndices_.end() ) {
                                                        std::cerr << "ERROR in LauSimFitMaster::finalise : Unexpected parameter name received from slave" << std::endl;
                                                        allOK = kFALSE;
                                                        continue;
                                                }

                                                const UInt_t index = iter->second;
                                                if ( slaveIndices_[iSlave][iPar] != index ) {
                                                        std::cerr << "ERROR in LauSimFitMaster::finalise : Unexpected parameter received from slave" << std::endl;
                                                        allOK = kFALSE;
                                                        continue;
                                                }

                                                Double_t parvalue = parameter->value();
                                                params_[index]->value( parvalue );
                                                parValues_[index] = parvalue;
                                                vectorPar_[iSlave][iPar] = parvalue;
                                        }
                                }
                                delete objarray;
                        }
                } else {
                        std::cerr << "ERROR in LauSimFitMaster::finalise : Slave " << iSlave << " reports an error performing finalisation" << std::endl;
                        allOK = kFALSE;
                }

                ++responsesReceived;
        }

        // Fill our ntuple as well
        if ( fitNtuple_ != 0 ) {
                for ( std::vector<LauParameter*>::iterator iter = params_.begin(); iter != params_.end(); ++iter ) {
                        if (!(*iter)->fixed()) {
                                (*iter)->updatePull();
                        }
                }
                std::vector<LauParameter> extraVars;
                fitNtuple_->storeParsAndErrors( params_, extraVars );
                fitNtuple_->storeCorrMatrix( iExpt_, NLL_, fitStatus_, covMatrix_ );
                fitNtuple_->updateFitNtuple();
        }

        return allOK;
}

Bool_t LauSimFitMaster::writeOutResults()
{
        if ( socketMonitor_ == 0 ) {
                std::cerr << "ERROR in LauSimFitMaster::writeOutResults : Sockets not initialised." << std::endl;
                return kFALSE;
        }

        // Construct a message, requesting to write out the fit results
        TString msgStr("Write Results");
        TMessage message( kMESS_STRING );
        message.WriteTString( msgStr );

        // Send the message to the slaves
        for ( UInt_t iSlave(0); iSlave<nSlaves_; ++iSlave ) {
                sSlaves_[iSlave]->Send(message);
        }

        TSocket  *sActive(0);
        UInt_t responsesReceived(0);
        Bool_t allOK(kTRUE);
        while ( responsesReceived != nSlaves_ ) {

                // Get the next queued response
                sActive = socketMonitor_->Select();

                // Extract from the message the ID of the slave and the number of events read
                sActive->Recv( messageFromSlave_ );
                UInt_t iSlave(0);
                Bool_t ok(kTRUE);
                messageFromSlave_->ReadUInt( iSlave );
                messageFromSlave_->ReadBool( ok );

                if ( ! ok ) {
                        std::cerr << "ERROR in LauSimFitMaster::writeOutResults : Slave " << iSlave << " reports an error performing finalisation" << std::endl;
                        allOK = kFALSE;
                }

                ++responsesReceived;
        }

        // Write out our ntuple as well
        if (fitNtuple_ != 0) {
                fitNtuple_->writeOutFitResults();
        }

        return allOK;
}