ITK
6.0.0
Insight Toolkit
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#include <itkParticleSwarmOptimizer.h>
Implementation of a Particle Swarm Optimization (PSO) algorithm.
The PSO algorithm was originally presented in:
J. Kennedy, R. Eberhart, "Particle Swarm Optimization", Proc. IEEE Int. Neural Networks, 1995.
The algorithm uses a stochastic optimization approach. Optimization is performed by maintaining a swarm (flock) of particles that traverse the parameter space, searching for the optimal function value. Associated with each particle are its location and speed, in parameter space. A particle's next location is determined by its current location, its current speed, the location of the best function value it previously encountered, and the location of the best function value the particles in its neighborhood previously encountered. In this implementation we use a global neighborhood with the following update equations:
\[v_i(t+1) = wv_i(t) + c_1u_1(p_i-x_i(t)) + c_2u_2(p_g-x_i(t))\]
\[x_i(t+1) = clampToBounds(x_i(t) + v_i(t+1))\]
where \(u_i\) are \(~U(0,1)\) and \(w,c_1,c_2\) are user selected weights.
Swarm initialization is performed within the user supplied parameter bounds using a uniform distribution or a normal distribution centered on the initial parameter values supplied by the user. The search terminates when the maximal number of iterations has been reached or when the change in the best value in the past \(g\) generations is below a threshold and the swarm has collapsed (i.e. particles are close to each other in parameter space).
NOTE: This implementation only performs minimization.
Definition at line 60 of file itkParticleSwarmOptimizer.h.
Public Member Functions | |
const char * | GetNameOfClass () const override |
virtual void | SetInertiaCoefficient (double _arg) |
virtual double | GetInertiaCoefficient () |
virtual void | SetPersonalCoefficient (double _arg) |
virtual double | GetPersonalCoefficient () |
virtual void | SetGlobalCoefficient (double _arg) |
virtual double | GetGlobalCoefficient () |
Public Member Functions inherited from itk::ParticleSwarmOptimizerBase | |
virtual MeasureType | GetFunctionConvergenceTolerance () |
const char * | GetNameOfClass () const override |
ParameterBoundsType | GetParameterBounds () const |
std::string | GetStopConditionDescription () const override |
MeasureType | GetValue () const |
void | PrintSwarm (std::ostream &os, Indent indent) const |
virtual void | SetFunctionConvergenceTolerance (MeasureType _arg) |
void | StartOptimization () override |
virtual void | SetInitializeNormalDistribution (bool _arg) |
virtual bool | GetInitializeNormalDistribution () |
virtual void | InitializeNormalDistributionOn () |
void | SetInitialSwarm (const SwarmType &initialSwarm) |
void | ClearSwarm () |
virtual void | SetPrintSwarm (bool _arg) |
virtual bool | GetPrintSwarm () |
virtual void | PrintSwarmOn () |
void | SetNumberOfParticles (NumberOfParticlesType n) |
virtual NumberOfParticlesType | GetNumberOfParticles () |
virtual void | SetMaximalNumberOfIterations (NumberOfIterationsType _arg) |
virtual NumberOfIterationsType | GetMaximalNumberOfIterations () |
virtual void | SetNumberOfGenerationsWithMinimalImprovement (NumberOfGenerationsType _arg) |
virtual NumberOfGenerationsType | GetNumberOfGenerationsWithMinimalImprovement () |
virtual void | SetParameterBounds (ParameterBoundsType &bounds) |
void | SetParameterBounds (std::pair< ParametersType::ValueType, ParametersType::ValueType > &bounds, unsigned int n) |
void | SetParametersConvergenceTolerance (ValueType convergenceTolerance, unsigned int sz) |
virtual void | SetParametersConvergenceTolerance (ParametersType _arg) |
virtual ParametersType | GetParametersConvergenceTolerance () |
virtual double | GetPercentageParticlesConverged () |
virtual void | SetPercentageParticlesConverged (double _arg) |
virtual void | SetSeed (RandomVariateGeneratorType::IntegerType _arg) |
virtual RandomVariateGeneratorType::IntegerType | GetSeed () |
virtual void | SetUseSeed (bool _arg) |
virtual bool | GetUseSeed () |
virtual void | UseSeedOn () |
Public Member Functions inherited from itk::SingleValuedNonLinearOptimizer | |
virtual CostFunctionType * | GetModifiableCostFunction () |
const char * | GetNameOfClass () const override |
MeasureType | GetValue (const ParametersType ¶meters) const |
virtual void | SetCostFunction (CostFunctionType *costFunction) |
const char * | GetNameOfClass () const override |
Public Member Functions inherited from itk::Optimizer | |
virtual const ParametersType & | GetCurrentPosition () const |
virtual const ParametersType & | GetInitialPosition () const |
const char * | GetNameOfClass () const override |
virtual std::string | GetStopConditionDescription () const |
virtual void | SetInitialPosition (const ParametersType ¶m) |
void | SetScales (const ScalesType &scales) |
virtual void | StartOptimization () |
virtual const ScalesType & | GetScales () const |
virtual const ScalesType & | GetInverseScales () const |
Public Member Functions inherited from itk::Object | |
unsigned long | AddObserver (const EventObject &event, Command *cmd) const |
unsigned long | AddObserver (const EventObject &event, std::function< void(const EventObject &)> function) const |
LightObject::Pointer | CreateAnother () const override |
virtual void | DebugOff () const |
virtual void | DebugOn () const |
Command * | GetCommand (unsigned long tag) |
bool | GetDebug () const |
MetaDataDictionary & | GetMetaDataDictionary () |
const MetaDataDictionary & | GetMetaDataDictionary () const |
virtual ModifiedTimeType | GetMTime () const |
const char * | GetNameOfClass () const override |
virtual const TimeStamp & | GetTimeStamp () const |
bool | HasObserver (const EventObject &event) const |
void | InvokeEvent (const EventObject &) |
void | InvokeEvent (const EventObject &) const |
virtual void | Modified () const |
void | Register () const override |
void | RemoveAllObservers () |
void | RemoveObserver (unsigned long tag) const |
void | SetDebug (bool debugFlag) const |
void | SetReferenceCount (int) override |
void | UnRegister () const noexcept override |
void | SetMetaDataDictionary (const MetaDataDictionary &rhs) |
void | SetMetaDataDictionary (MetaDataDictionary &&rrhs) |
virtual void | SetObjectName (std::string _arg) |
virtual const std::string & | GetObjectName () const |
Public Member Functions inherited from itk::LightObject | |
Pointer | Clone () const |
virtual Pointer | CreateAnother () const |
virtual void | Delete () |
virtual const char * | GetNameOfClass () const |
virtual int | GetReferenceCount () const |
void | Print (std::ostream &os, Indent indent=0) const |
virtual void | Register () const |
virtual void | SetReferenceCount (int) |
virtual void | UnRegister () const noexcept |
Static Public Member Functions | |
static Pointer | New () |
Static Public Member Functions inherited from itk::SingleValuedNonLinearOptimizer | |
static Pointer | New () |
Static Public Member Functions inherited from itk::NonLinearOptimizer | |
static Pointer | New () |
Static Public Member Functions inherited from itk::Optimizer | |
static Pointer | New () |
Static Public Member Functions inherited from itk::Object | |
static bool | GetGlobalWarningDisplay () |
static void | GlobalWarningDisplayOff () |
static void | GlobalWarningDisplayOn () |
static Pointer | New () |
static void | SetGlobalWarningDisplay (bool val) |
Static Public Member Functions inherited from itk::LightObject | |
static void | BreakOnError () |
static Pointer | New () |
Protected Member Functions | |
ParticleSwarmOptimizer () | |
void | PrintSelf (std::ostream &os, Indent indent) const override |
void | UpdateSwarm () override |
~ParticleSwarmOptimizer () override | |
Protected Member Functions inherited from itk::ParticleSwarmOptimizerBase | |
void | FileInitialization () |
virtual void | Initialize () |
ParticleSwarmOptimizerBase () | |
void | PrintParamtersType (const ParametersType &x, std::ostream &os) const |
void | PrintSelf (std::ostream &os, Indent indent) const override |
void | RandomInitialization () |
virtual void | UpdateSwarm ()=0 |
virtual void | ValidateSettings () |
~ParticleSwarmOptimizerBase () override | |
Protected Member Functions inherited from itk::SingleValuedNonLinearOptimizer | |
void | PrintSelf (std::ostream &os, Indent indent) const override |
SingleValuedNonLinearOptimizer () | |
~SingleValuedNonLinearOptimizer () override=default | |
Protected Member Functions inherited from itk::NonLinearOptimizer | |
NonLinearOptimizer ()=default | |
~NonLinearOptimizer () override | |
Protected Member Functions inherited from itk::Optimizer | |
Optimizer () | |
void | PrintSelf (std::ostream &os, Indent indent) const override |
virtual void | SetCurrentPosition (const ParametersType ¶m) |
~Optimizer () override=default | |
Protected Member Functions inherited from itk::Object | |
Object () | |
bool | PrintObservers (std::ostream &os, Indent indent) const |
void | PrintSelf (std::ostream &os, Indent indent) const override |
virtual void | SetTimeStamp (const TimeStamp &timeStamp) |
~Object () override | |
Protected Member Functions inherited from itk::LightObject | |
virtual LightObject::Pointer | InternalClone () const |
LightObject () | |
virtual void | PrintHeader (std::ostream &os, Indent indent) const |
virtual void | PrintSelf (std::ostream &os, Indent indent) const |
virtual void | PrintTrailer (std::ostream &os, Indent indent) const |
virtual | ~LightObject () |
Private Attributes | |
ParametersType::ValueType | m_GlobalCoefficient {} |
ParametersType::ValueType | m_InertiaCoefficient {} |
ParametersType::ValueType | m_PersonalCoefficient {} |
using itk::ParticleSwarmOptimizer::ConstPointer = SmartPointer<const Self> |
Definition at line 69 of file itkParticleSwarmOptimizer.h.
Definition at line 68 of file itkParticleSwarmOptimizer.h.
Standard "Self" type alias.
Definition at line 66 of file itkParticleSwarmOptimizer.h.
Definition at line 67 of file itkParticleSwarmOptimizer.h.
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The Particle swarm optimizer uses the following update formula: v_i(t+1) = w*v_i(t) + c_1*uniform(0,1)*(p_i-x_i(t)) + c_2*uniform(0,1)*(p_g-x_i(t)) x_i(t+1) = clampToBounds(x_i(t) + v_i(t+1)) where w - inertia constant c_1 - personal coefficient c_2 - global coefficient p_i - parameters yielding the best function value obtained by this particle p_g - parameters yielding the best function value obtained by all particles
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The Particle swarm optimizer uses the following update formula: v_i(t+1) = w*v_i(t) + c_1*uniform(0,1)*(p_i-x_i(t)) + c_2*uniform(0,1)*(p_g-x_i(t)) x_i(t+1) = clampToBounds(x_i(t) + v_i(t+1)) where w - inertia constant c_1 - personal coefficient c_2 - global coefficient p_i - parameters yielding the best function value obtained by this particle p_g - parameters yielding the best function value obtained by all particles
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Reimplemented from itk::NonLinearOptimizer.
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The Particle swarm optimizer uses the following update formula: v_i(t+1) = w*v_i(t) + c_1*uniform(0,1)*(p_i-x_i(t)) + c_2*uniform(0,1)*(p_g-x_i(t)) x_i(t+1) = clampToBounds(x_i(t) + v_i(t+1)) where w - inertia constant c_1 - personal coefficient c_2 - global coefficient p_i - parameters yielding the best function value obtained by this particle p_g - parameters yielding the best function value obtained by all particles
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Method for creation through the object factory.
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Methods invoked by Print() to print information about the object including superclasses. Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.
Reimplemented from itk::Optimizer.
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The Particle swarm optimizer uses the following update formula: v_i(t+1) = w*v_i(t) + c_1*uniform(0,1)*(p_i-x_i(t)) + c_2*uniform(0,1)*(p_g-x_i(t)) x_i(t+1) = clampToBounds(x_i(t) + v_i(t+1)) where w - inertia constant c_1 - personal coefficient c_2 - global coefficient p_i - parameters yielding the best function value obtained by this particle p_g - parameters yielding the best function value obtained by all particles
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The Particle swarm optimizer uses the following update formula: v_i(t+1) = w*v_i(t) + c_1*uniform(0,1)*(p_i-x_i(t)) + c_2*uniform(0,1)*(p_g-x_i(t)) x_i(t+1) = clampToBounds(x_i(t) + v_i(t+1)) where w - inertia constant c_1 - personal coefficient c_2 - global coefficient p_i - parameters yielding the best function value obtained by this particle p_g - parameters yielding the best function value obtained by all particles
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The Particle swarm optimizer uses the following update formula: v_i(t+1) = w*v_i(t) + c_1*uniform(0,1)*(p_i-x_i(t)) + c_2*uniform(0,1)*(p_g-x_i(t)) x_i(t+1) = clampToBounds(x_i(t) + v_i(t+1)) where w - inertia constant c_1 - personal coefficient c_2 - global coefficient p_i - parameters yielding the best function value obtained by this particle p_g - parameters yielding the best function value obtained by all particles
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Implement your update rule in this function.
Implements itk::ParticleSwarmOptimizerBase.
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Definition at line 108 of file itkParticleSwarmOptimizer.h.
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Definition at line 106 of file itkParticleSwarmOptimizer.h.
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Definition at line 107 of file itkParticleSwarmOptimizer.h.