DESolver Class Reference

#include <numerical_tools.h>

Inheritance diagram for DESolver:

Public Member Functions
	DESolver (int dim, int popSize)
	Empty constructor. More...
	DESolver (const DESolver &)=delete
DESolver &	operator= (const DESolver &)=delete
virtual	~DESolver (void)
	Destructor. More...
void	Setup (double min[], double max[], int deStrategy, double diffScale, double crossoverProb)
	Setup() must be called before solve to set min, max, strategy etc. More...
virtual bool	Solve (int maxGenerations)
virtual double	EnergyFunction (double testSolution[], bool &bAtSolution)=0
int	Dimension () const
	Return dimension. More...
int	Population () const
	Return population. More...
double	Energy () const
	Call these functions after Solve() to get results. More...
double *	Solution (void)
	Return best solution. More...
int	Generations () const
	Return the number of generations. More...

Protected Member Functions
void	SelectSamples (int candidate, int *r1, int *r2=nullptr, int *r3=nullptr, int *r4=nullptr, int *r5=nullptr)

Protected Attributes
int	nDim
int	nPop
int	generations
int	strategy
StrategyFunction	calcTrialSolution
double	scale
double	probability
double	trialEnergy
double	bestEnergy
double *	trialSolution
double *	bestSolution
double *	popEnergy
double *	population

Detailed Description

Differential evolution class. For further information visit: http://www.icsi.berkeley.edu/~storn/code.html Example of use:

// Declaration of the optimizer
class AlignmentSolver : public DESolver {
public:
   AlignmentSolver(int dim,int pop) : DESolver(dim,pop), count(0) {;}
   double EnergyFunction(double trial[],bool &bAtSolution) {
      double result=wrapper_fitness_individual(trial);
      if (count++ % (5*nPop) == 0)
          std::cout << "Evaluations= " << count/nPop
                    << " energy= " << Energy()
                << " axisRot= " << Solution()[0]
                << " axisTilt= " << Solution()[1]
                << " axisShiftX= " << Solution()[2]
                << " axisShiftY= " << Solution()[3]
                << " axisShiftZ= " << Solution()[4]
            << std::endl;
      bAtSolution=false;
      return(result);
   }
private:
   int count;
};

// Optimizer use:
       AlignmentSolver solver(length,length*Npop);
       solver.Setup(MULTIDIM_ARRAY(min_allowed),
                    MULTIDIM_ARRAY(max_allowed), stBest2Bin, 0.5, 0.8);
       solver.Solve(NGenerations);
       double current_energy=solver.Energy();
       double* bestSolution=solver.Solution();

Definition at line 312 of file numerical_tools.h.

Constructor & Destructor Documentation

DESolver() [1/2]

DESolver::DESolver	(	int	dim,
		int	popSize
	)

Empty constructor.

Definition at line 387 of file numerical_tools.cpp.

                                       :
nDim(dim), nPop(popSize),
generations(0), strategy(stRand1Exp),
scale(0.7), probability(0.5), bestEnergy(0.0),
trialSolution(0), bestSolution(0),
popEnergy(0), population(0)
{
    trialSolution = new double[nDim];
    bestSolution  = new double[nDim];
    popEnergy   = new double[nPop];
    population   = new double[nPop * nDim];

    randomize_random_generator();
}

DESolver() [2/2]

DESolver::DESolver ( const DESolver &  )

delete

~DESolver()

DESolver::~DESolver ( void  )

virtual

Destructor.

Definition at line 402 of file numerical_tools.cpp.

{
    if (trialSolution)
        delete [] trialSolution;
    if (bestSolution)
        delete [] bestSolution;
    if (popEnergy)
        delete [] popEnergy;
    if (population)
        delete [] population;

    trialSolution = bestSolution = popEnergy = population = nullptr;
    return;
}

Member Function Documentation

Dimension()

int DESolver::Dimension ( ) const

inline

Return dimension.

Definition at line 344 of file numerical_tools.h.

    {
        return nDim;
    }

Energy()

double DESolver::Energy ( ) const

inline

Call these functions after Solve() to get results.

Definition at line 356 of file numerical_tools.h.

    {
        return bestEnergy;
    }

EnergyFunction()

virtual double DESolver::EnergyFunction ( double  testSolution[], bool &  bAtSolution  )

pure virtual

EnergyFunction must be overridden for problem to solve testSolution[] is nDim array for a candidate solution setting bAtSolution = true indicates solution is found and Solve() immediately returns true.

Implemented in WedgeSolver, and EulerSolver.

Generations()

int DESolver::Generations ( ) const

inline

Return the number of generations.

Definition at line 368 of file numerical_tools.h.

    {
        return generations;
    }

operator=()

DESolver& DESolver::operator= ( const DESolver &  )

delete

Population()

int DESolver::Population ( ) const

inline

Return population.

Definition at line 350 of file numerical_tools.h.

    {
        return nPop;
    }

SelectSamples()

void DESolver::SelectSamples ( int  candidate, int *  r1, int *  r2 = nullptr, int *  r3 = nullptr, int *  r4 = nullptr, int *  r5 = nullptr  )

protected

Definition at line 749 of file numerical_tools.cpp.

{
    if (r1)
    {
        do
        {
            *r1 = (int)rnd_unif(0.0, (double)nPop);
        }
        while (*r1 == candidate);
    } else
        return;

    if (r2)
    {
        do
        {
            *r2 = (int)rnd_unif(0.0, (double)nPop);
        }
        while ((*r2 == candidate) || (*r2 == *r1));
    } else
        return;

    if (r3)
    {
        do
        {
            *r3 = (int)rnd_unif(0.0, (double)nPop);
        }
        while ((*r3 == candidate) || (*r3 == *r2) || (*r3 == *r1));
    } else
        return;

    if (r4)
    {
        do
        {
            *r4 = (int)rnd_unif(0.0, (double)nPop);
        }
        while ((*r4 == candidate) || (*r4 == *r3) || (*r4 == *r2) || (*r4 == *r1));
    } else
        return;

    if (r5)
    {
        do
        {
            *r5 = (int)rnd_unif(0.0, (double)nPop);
        }
        while ((*r5 == candidate) || (*r5 == *r4) || (*r5 == *r3)
               || (*r5 == *r2) || (*r5 == *r1));
    }
}

Setup()

void DESolver::Setup	(	double	min[],
		double	max[],
		int	deStrategy,
		double	diffScale,
		double	crossoverProb
	)

Setup() must be called before solve to set min, max, strategy etc.

Definition at line 417 of file numerical_tools.cpp.

{
    int i;
    int j;

    strategy = deStrategy;
    scale  = diffScale;
    probability     = crossoverProb;
    bestEnergy      = 1.0E20;

    for (i = 0; i < nPop; i++)
    {
        for (j = 0; j < nDim; j++)
        {
            population[i*nDim+j] = rnd_unif(min[j], max[j]);
            //Element(population, i, j) = rnd_unif(min[j], max[j]);
        }

        popEnergy[i] = 1.0E20;
    }

    for (i = 0; i < nDim; i++)
        bestSolution[i] = (min[i] + max[i]) / 2.0;

    switch (strategy)
    {
    case stBest1Exp:
        calcTrialSolution = &DESolver::Best1Exp;
        break;

    case stRand1Exp:
        calcTrialSolution = &DESolver::Rand1Exp;
        break;

    case stRandToBest1Exp:
        calcTrialSolution = &DESolver::RandToBest1Exp;
        break;

    case stBest2Exp:
        calcTrialSolution = &DESolver::Best2Exp;
        break;

    case stRand2Exp:
        calcTrialSolution = &DESolver::Rand2Exp;
        break;

    case stBest1Bin:
        calcTrialSolution = &DESolver::Best1Bin;
        break;

    case stRand1Bin:
        calcTrialSolution = &DESolver::Rand1Bin;
        break;

    case stRandToBest1Bin:
        calcTrialSolution = &DESolver::RandToBest1Bin;
        break;

    case stBest2Bin:
        calcTrialSolution = &DESolver::Best2Bin;
        break;

    case stRand2Bin:
        calcTrialSolution = &DESolver::Rand2Bin;
        break;
    }

    return;
}

Solution()

double* DESolver::Solution ( void  )

inline

Return best solution.

Definition at line 362 of file numerical_tools.h.

    {
        return bestSolution;
    }

Solve()

bool DESolver::Solve ( int  maxGenerations )

virtual

Solve() returns true if EnergyFunction() returns true. Otherwise it runs maxGenerations generations and returns false.

Definition at line 488 of file numerical_tools.cpp.

{
    bool bAtSolution = false;
    int generation;

    for (generation = 0;(generation < maxGenerations) && !bAtSolution;generation++)
        for (int candidate = 0; candidate < nPop; candidate++)
        {
            (this->*calcTrialSolution)(candidate);
            trialEnergy = EnergyFunction(trialSolution, bAtSolution);

            if (trialEnergy < popEnergy[candidate])
            {
                // New low for this candidate
                popEnergy[candidate] = trialEnergy;
                CopyVector(RowVector(population, candidate), trialSolution);

                // Check if all-time low
                if (trialEnergy < bestEnergy)
                {
                    bestEnergy = trialEnergy;
                    CopyVector(bestSolution, trialSolution);
                }
            }
        }

    generations = generation;
    return bAtSolution;
}

Member Data Documentation

bestEnergy

double DESolver::bestEnergy

protected

Definition at line 391 of file numerical_tools.h.

bestSolution

double* DESolver::bestSolution

protected

Definition at line 394 of file numerical_tools.h.

calcTrialSolution

StrategyFunction DESolver::calcTrialSolution

protected

Definition at line 386 of file numerical_tools.h.

generations

int DESolver::generations

protected

Definition at line 383 of file numerical_tools.h.

nDim

int DESolver::nDim

protected

Definition at line 381 of file numerical_tools.h.

nPop

int DESolver::nPop

protected

Definition at line 382 of file numerical_tools.h.

popEnergy

double* DESolver::popEnergy

protected

Definition at line 395 of file numerical_tools.h.

population

double* DESolver::population

protected

Definition at line 396 of file numerical_tools.h.

probability

double DESolver::probability

protected

Definition at line 388 of file numerical_tools.h.

scale

double DESolver::scale

protected

Definition at line 387 of file numerical_tools.h.

strategy

int DESolver::strategy

protected

Definition at line 385 of file numerical_tools.h.

trialEnergy

double DESolver::trialEnergy

protected

Definition at line 390 of file numerical_tools.h.

trialSolution

double* DESolver::trialSolution

protected

Definition at line 393 of file numerical_tools.h.

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The documentation for this class was generated from the following files:

• xmipp/libraries/data/numerical_tools.h
• xmipp/libraries/data/numerical_tools.cpp