1 files changed, 139 insertions, 0 deletions

diff --git a/src/explicitsimulation.cpp b/src/explicitsimulation.cpp
new file mode 100644
index 0000000..281e7e5
--- /dev/null
+++ b/src/explicitsimulation.cpp
@@ -0,0 +1,139 @@
+#include "genetic/explicitsimulation.h"
+#include "genetic/operator.h"
+#include "genetic/fitnessfunction.h"
+
+#include <bu/random.h>
+#include <bu/sio.h>
+
+using namespace Bu;
+
+Genetic::ExplicitSimulation::ExplicitSimulation( Genetic::Operator *pOper,
+                Genetic::FitnessFunction *pFunc, int iPopSize, float fKeep,
+                float fRandom, bool bKeepBest ) :
+        pOper( pOper ),
+        pFunc( pFunc ),
+        iPopSize( iPopSize ),
+        fKeep( fKeep ),
+        fRandom( fRandom ),
+        bKeepBest( bKeepBest )
+{
+        for( int j = 0; j < iPopSize; j++ )
+        {
+                xPop.addPhenotype( pOper->random() );
+        }
+
+        updateFitness();
+}
+
+Genetic::ExplicitSimulation::~ExplicitSimulation()
+{
+        delete pOper;
+        delete pFunc;
+}
+
+void Genetic::ExplicitSimulation::timestep()
+{
+        PhenotypeList lNew;
+        
+        int iChildren = iPopSize*(1.0-fKeep-fRandom);
+
+        // Create children
+        for( int j = 0; j < iChildren; j++ )
+        {
+                PhenotypeList lParents;
+                for( int k = 0; k < pOper->parentCount(); k++ )
+                        lParents.append( xPop.getPhenotype( selectWeighted() ) );
+                lNew.append( pOper->mate( lParents ) );
+        }
+
+        // Select phenotypes for keeping
+        int iKeep = iPopSize*fKeep;
+        FitnessHash hTempFitness;
+        for( int j = 0; j < iKeep; j++ )
+        {
+                Genetic::PhenotypeId id = selectWeighted();
+                lNew.append( xPop.takePhenotype( id ) );
+                hTempFitness.insert( id, hFitness.get( id ) );
+                hFitness.erase( id );
+                dTotalFitness -= hTempFitness.get( id );
+        }
+
+        if( bKeepBest && hFitness.has( uMaxFitness ) )
+        {
+                lNew.append( xPop.takePhenotype( uMaxFitness ) );
+                hTempFitness.insert( uMaxFitness, hFitness.get( uMaxFitness ) );
+                hFitness.erase( uMaxFitness );
+                dTotalFitness -= hTempFitness.get( uMaxFitness );
+        }
+
+        // Fill in the remainder with random phenotypes
+        while( lNew.getSize() < iPopSize )
+        {
+                lNew.append( pOper->random() );
+        }
+
+        // Refill the population
+        hFitness = hTempFitness;
+        xPop.clear();
+        xPop.timestep();
+        for( PhenotypeList::iterator i = lNew.begin(); i; i++ )
+        {
+                xPop.addPhenotype( *i );
+        }
+
+        updateFitness();
+}
+
+Genetic::PhenotypeId Genetic::ExplicitSimulation::selectWeighted()
+{
+        double dSel = Bu::Random::randNorm()*dTotalFitness;
+        double dRun = 0.0;
+
+        for( FitnessHash::iterator i = hFitness.begin(); i; i++ )
+        {
+                dRun += *i;
+                if( dSel < dRun )
+                        return i.getKey();
+        }
+
+        sio << "Genetic::ExplicitSimulation::selectWeighted() - failed, picked max"
+                << sio.nl;
+
+        return uMaxFitness;
+}
+
+void Genetic::ExplicitSimulation::updateFitness()
+{
+        dMinFitness = -1.0;
+        dTotalFitness = 0.0;
+        for( Population::iterator i = xPop.begin(); i; i++ )
+        {
+                double dFitness;
+                if( hFitness.has( i.getKey() ) )
+                {
+                        dFitness = hFitness.get( i.getKey() );
+                }
+                else
+                {
+                        dFitness = (*pFunc)( *i );
+                        if( dFitness < 0.0 )
+                                dFitness = 0.0;
+                        hFitness.insert( i.getKey(), dFitness );
+                }
+                dTotalFitness += dFitness;
+                if( dMinFitness < 0.0 )
+                {
+                        dMinFitness = dMaxFitness = dFitness;
+                        uMaxFitness = i.getKey();
+                }
+                else if( dMinFitness > dFitness )
+                {
+                        dMinFitness = dFitness;
+                }
+                else if( dMaxFitness < dFitness )
+                {
+                        dMaxFitness = dFitness;
+                        uMaxFitness = i.getKey();
+                }
+        }
+}