ITK
4.1.0
Insight Segmentation and Registration Toolkit
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#include <itkPowellOptimizer.h>
Public Types | |
typedef SmartPointer< const Self > | ConstPointer |
typedef CostFunctionType::Pointer | CostFunctionPointer |
typedef SingleValuedCostFunction | CostFunctionType |
typedef SingleValuedNonLinearOptimizer::ParametersType | ParametersType |
typedef SmartPointer< Self > | Pointer |
typedef PowellOptimizer | Self |
typedef SingleValuedNonLinearOptimizer | Superclass |
Public Member Functions | |
virtual ::itk::LightObject::Pointer | CreateAnother (void) const |
virtual const bool & | GetCatchGetValueException () |
virtual const unsigned int & | GetCurrentIteration () |
virtual const unsigned int & | GetCurrentLineIteration () |
virtual const double & | GetMetricWorstPossibleValue () |
virtual const char * | GetNameOfClass () const |
const std::string | GetStopConditionDescription () const |
virtual void | SetCatchGetValueException (bool _arg) |
virtual void | SetMetricWorstPossibleValue (double _arg) |
void | StartOptimization () |
void | StopOptimization () |
virtual void | SetMaximize (bool _arg) |
virtual void | MaximizeOn () |
virtual void | MaximizeOff () |
virtual const bool & | GetMaximize () |
virtual void | SetMaximumIteration (unsigned int _arg) |
virtual const unsigned int & | GetMaximumIteration () |
virtual void | SetMaximumLineIteration (unsigned int _arg) |
virtual unsigned int | GetMaximumLineIteration () const |
virtual void | SetStepLength (double _arg) |
virtual const double & | GetStepLength () |
virtual void | SetStepTolerance (double _arg) |
virtual const double & | GetStepTolerance () |
virtual void | SetValueTolerance (double _arg) |
virtual const double & | GetValueTolerance () |
virtual const MeasureType & | GetCurrentCost () |
MeasureType | GetValue () const |
Static Public Member Functions | |
static Pointer | New () |
Protected Member Functions | |
virtual void | BracketedLineOptimize (double ax, double bx, double cx, double fa, double fb, double fc, double *extX, double *extVal) |
virtual void | BracketedLineOptimize (double ax, double bx, double cx, double fa, double fb, double fc, double *extX, double *extVal, ParametersType &tempCoord) |
double | GetLineValue (double x) const |
double | GetLineValue (double x, ParametersType &tempCoord) const |
virtual unsigned int | GetSpaceDimension () |
virtual bool | GetStop () |
virtual void | LineBracket (double *ax, double *bx, double *cx, double *fa, double *fb, double *fc) |
virtual void | LineBracket (double *ax, double *bx, double *cx, double *fa, double *fb, double *fc, ParametersType &tempCoord) |
PowellOptimizer () | |
PowellOptimizer (const PowellOptimizer &) | |
void | PrintSelf (std::ostream &os, Indent indent) const |
virtual void | SetCurrentCost (double _arg) |
virtual void | SetCurrentIteration (unsigned int _arg) |
void | SetCurrentLinePoint (double x, double fx) |
void | SetLine (const ParametersType &origin, const vnl_vector< double > &direction) |
void | SetSpaceDimension (unsigned int dim) |
virtual void | SetStop (bool _arg) |
void | Shift (double *a, double *b, double *c, double d) const |
void | Swap (double *a, double *b) const |
virtual | ~PowellOptimizer () |
Private Attributes | |
bool | m_CatchGetValueException |
MeasureType | m_CurrentCost |
unsigned int | m_CurrentIteration |
unsigned int | m_CurrentLineIteration |
vnl_vector< double > | m_LineDirection |
ParametersType | m_LineOrigin |
bool | m_Maximize |
unsigned int | m_MaximumIteration |
unsigned int | m_MaximumLineIteration |
double | m_MetricWorstPossibleValue |
unsigned int | m_SpaceDimension |
double | m_StepLength |
double | m_StepTolerance |
bool | m_Stop |
std::ostringstream | m_StopConditionDescription |
double | m_ValueTolerance |
Implements Powell optimization using Brent line search.
The code in this class was adapted from the Wikipedia and the netlib.org zeroin function.
http://www.netlib.org/go/zeroin.f http://en.wikipedia.org/wiki/Brent_method http://en.wikipedia.org/wiki/Golden_section_search
This optimizer needs a cost function. Partial derivatives of that function are not required.
For an N-dimensional parameter space, each iteration minimizes(maximizes) the function in N (initially orthogonal) directions. Typically only 2-5 iterations are required. If gradients are available, consider a conjugate gradient line search strategy.
The SetStepLength determines the initial distance to step in a line direction when bounding the minimum (using bracketing triple spaced using a golden search strategy).
The StepTolerance terminates optimization when the parameter values are known to be within this (scaled) distance of the local extreme.
The ValueTolerance terminates optimization when the cost function values at the current parameters and at the local extreme are likely (within a second order approximation) to be within this is tolerance.
Definition at line 61 of file itkPowellOptimizer.h.
typedef SmartPointer< const Self > itk::PowellOptimizer::ConstPointer |
Reimplemented from itk::SingleValuedNonLinearOptimizer.
Reimplemented in itk::FRPROptimizer.
Definition at line 69 of file itkPowellOptimizer.h.
Reimplemented from itk::SingleValuedNonLinearOptimizer.
Reimplemented in itk::FRPROptimizer.
Definition at line 82 of file itkPowellOptimizer.h.
Type of the Cost Function
Reimplemented from itk::SingleValuedNonLinearOptimizer.
Reimplemented in itk::FRPROptimizer.
Definition at line 78 of file itkPowellOptimizer.h.
Parameters type. It defines a position in the optimization search space.
Reimplemented from itk::SingleValuedNonLinearOptimizer.
Reimplemented in itk::FRPROptimizer.
Definition at line 72 of file itkPowellOptimizer.h.
typedef SmartPointer< Self > itk::PowellOptimizer::Pointer |
Reimplemented from itk::SingleValuedNonLinearOptimizer.
Reimplemented in itk::FRPROptimizer.
Definition at line 68 of file itkPowellOptimizer.h.
Standard "Self" typedef.
Reimplemented from itk::SingleValuedNonLinearOptimizer.
Reimplemented in itk::FRPROptimizer.
Definition at line 66 of file itkPowellOptimizer.h.
Reimplemented from itk::SingleValuedNonLinearOptimizer.
Reimplemented in itk::FRPROptimizer.
Definition at line 67 of file itkPowellOptimizer.h.
itk::PowellOptimizer::PowellOptimizer | ( | ) | [protected] |
itk::PowellOptimizer::PowellOptimizer | ( | const PowellOptimizer & | ) | [protected] |
virtual itk::PowellOptimizer::~PowellOptimizer | ( | ) | [protected, virtual] |
virtual void itk::PowellOptimizer::BracketedLineOptimize | ( | double | ax, |
double | bx, | ||
double | cx, | ||
double | fa, | ||
double | fb, | ||
double | fc, | ||
double * | extX, | ||
double * | extVal | ||
) | [protected, virtual] |
Given a bracketing triple of points and their function values, returns a bounded extreme. These values are in parameter space, along the current line and wrt the current origin set via SetLine. Optimization terminates based on MaximumIteration, StepTolerance, or ValueTolerance. Implemented as Brent line optimers from NRC.
virtual void itk::PowellOptimizer::BracketedLineOptimize | ( | double | ax, |
double | bx, | ||
double | cx, | ||
double | fa, | ||
double | fb, | ||
double | fc, | ||
double * | extX, | ||
double * | extVal, | ||
ParametersType & | tempCoord | ||
) | [protected, virtual] |
virtual::itk::LightObject::Pointer itk::PowellOptimizer::CreateAnother | ( | void | ) | const [virtual] |
Create an object from an instance, potentially deferring to a factory. This method allows you to create an instance of an object that is exactly the same type as the referring object. This is useful in cases where an object has been cast back to a base class.
Reimplemented from itk::SingleValuedNonLinearOptimizer.
Reimplemented in itk::FRPROptimizer.
virtual const bool& itk::PowellOptimizer::GetCatchGetValueException | ( | ) | [virtual] |
virtual const MeasureType& itk::PowellOptimizer::GetCurrentCost | ( | ) | [virtual] |
Return Current Value
virtual const unsigned int& itk::PowellOptimizer::GetCurrentIteration | ( | ) | [virtual] |
Return Current Iteration
virtual const unsigned int& itk::PowellOptimizer::GetCurrentLineIteration | ( | ) | [virtual] |
Get the current line search iteration
double itk::PowellOptimizer::GetLineValue | ( | double | x | ) | const [protected] |
Get the value of the n-dimensional cost function at this scalar step distance along the current line direction from the current line origin. Line origin and distances are set via SetLine
double itk::PowellOptimizer::GetLineValue | ( | double | x, |
ParametersType & | tempCoord | ||
) | const [protected] |
virtual const bool& itk::PowellOptimizer::GetMaximize | ( | ) | [virtual] |
Set if the Optimizer should Maximize the metric
virtual const unsigned int& itk::PowellOptimizer::GetMaximumIteration | ( | ) | [virtual] |
Set/Get maximum iteration limit.
virtual unsigned int itk::PowellOptimizer::GetMaximumLineIteration | ( | ) | const [virtual] |
Set/Get the maximum number of line search iterations
virtual const double& itk::PowellOptimizer::GetMetricWorstPossibleValue | ( | ) | [virtual] |
virtual const char* itk::PowellOptimizer::GetNameOfClass | ( | ) | const [virtual] |
Run-time type information (and related methods).
Reimplemented from itk::SingleValuedNonLinearOptimizer.
Reimplemented in itk::FRPROptimizer.
virtual unsigned int itk::PowellOptimizer::GetSpaceDimension | ( | ) | [protected, virtual] |
virtual const double& itk::PowellOptimizer::GetStepLength | ( | ) | [virtual] |
Set/Get StepLength for the (scaled) spacing of the sampling of parameter space while bracketing the extremum
virtual const double& itk::PowellOptimizer::GetStepTolerance | ( | ) | [virtual] |
Set/Get StepTolerance. Once the local extreme is known to be within this distance of the current parameter values, optimization terminates
virtual bool itk::PowellOptimizer::GetStop | ( | ) | [protected, virtual] |
const std::string itk::PowellOptimizer::GetStopConditionDescription | ( | ) | const [virtual] |
Get the reason for termination
Reimplemented from itk::Optimizer.
MeasureType itk::PowellOptimizer::GetValue | ( | ) | const [inline] |
Return Current Value
Definition at line 121 of file itkPowellOptimizer.h.
virtual const double& itk::PowellOptimizer::GetValueTolerance | ( | ) | [virtual] |
Set/Get ValueTolerance. Once this current cost function value is known to be within this tolerance of the cost function value at the local extreme, optimization terminates
virtual void itk::PowellOptimizer::LineBracket | ( | double * | ax, |
double * | bx, | ||
double * | cx, | ||
double * | fa, | ||
double * | fb, | ||
double * | fc | ||
) | [protected, virtual] |
The LineBracket routine from NRC. Later reimplemented from the description of the method available in the Wikipedia.
Uses current origin and line direction (from SetLine) to find a triple of points (ax, bx, cx) that bracket the extreme "near" the origin. Search first considers the point StepLength distance from ax.
IMPORTANT: The value of ax and the value of the function at ax (i.e., fa), must both be provided to this function.
virtual void itk::PowellOptimizer::LineBracket | ( | double * | ax, |
double * | bx, | ||
double * | cx, | ||
double * | fa, | ||
double * | fb, | ||
double * | fc, | ||
ParametersType & | tempCoord | ||
) | [protected, virtual] |
virtual void itk::PowellOptimizer::MaximizeOff | ( | ) | [virtual] |
Set if the Optimizer should Maximize the metric
virtual void itk::PowellOptimizer::MaximizeOn | ( | ) | [virtual] |
Set if the Optimizer should Maximize the metric
static Pointer itk::PowellOptimizer::New | ( | ) | [static] |
Method for creation through the object factory.
Reimplemented from itk::SingleValuedNonLinearOptimizer.
Reimplemented in itk::FRPROptimizer.
void itk::PowellOptimizer::PrintSelf | ( | std::ostream & | os, |
Indent | indent | ||
) | const [protected, virtual] |
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::SingleValuedNonLinearOptimizer.
Reimplemented in itk::FRPROptimizer.
virtual void itk::PowellOptimizer::SetCatchGetValueException | ( | bool | _arg | ) | [virtual] |
virtual void itk::PowellOptimizer::SetCurrentCost | ( | double | _arg | ) | [protected, virtual] |
virtual void itk::PowellOptimizer::SetCurrentIteration | ( | unsigned int | _arg | ) | [protected, virtual] |
void itk::PowellOptimizer::SetCurrentLinePoint | ( | double | x, |
double | fx | ||
) | [protected] |
Set the given scalar step distance (x) and function value (fx) as the "best-so-far" optimizer values.
void itk::PowellOptimizer::SetLine | ( | const ParametersType & | origin, |
const vnl_vector< double > & | direction | ||
) | [protected] |
Used to specify the line direction through the n-dimensional parameter space the is currently being bracketed and optimized.
virtual void itk::PowellOptimizer::SetMaximize | ( | bool | _arg | ) | [virtual] |
Set if the Optimizer should Maximize the metric
virtual void itk::PowellOptimizer::SetMaximumIteration | ( | unsigned int | _arg | ) | [virtual] |
Set/Get maximum iteration limit.
virtual void itk::PowellOptimizer::SetMaximumLineIteration | ( | unsigned int | _arg | ) | [virtual] |
Set/Get the maximum number of line search iterations
virtual void itk::PowellOptimizer::SetMetricWorstPossibleValue | ( | double | _arg | ) | [virtual] |
void itk::PowellOptimizer::SetSpaceDimension | ( | unsigned int | dim | ) | [inline, protected] |
Definition at line 210 of file itkPowellOptimizer.h.
virtual void itk::PowellOptimizer::SetStepLength | ( | double | _arg | ) | [virtual] |
Set/Get StepLength for the (scaled) spacing of the sampling of parameter space while bracketing the extremum
virtual void itk::PowellOptimizer::SetStepTolerance | ( | double | _arg | ) | [virtual] |
Set/Get StepTolerance. Once the local extreme is known to be within this distance of the current parameter values, optimization terminates
virtual void itk::PowellOptimizer::SetStop | ( | bool | _arg | ) | [protected, virtual] |
virtual void itk::PowellOptimizer::SetValueTolerance | ( | double | _arg | ) | [virtual] |
Set/Get ValueTolerance. Once this current cost function value is known to be within this tolerance of the cost function value at the local extreme, optimization terminates
void itk::PowellOptimizer::Shift | ( | double * | a, |
double * | b, | ||
double * | c, | ||
double | d | ||
) | const [protected] |
Used in bracketing the extreme along the current line. Adapted from NRC
void itk::PowellOptimizer::StartOptimization | ( | ) | [virtual] |
void itk::PowellOptimizer::StopOptimization | ( | ) | [inline] |
When users call StartOptimization, this value will be set false. By calling StopOptimization, this flag will be set true, and optimization will stop at the next iteration.
Definition at line 136 of file itkPowellOptimizer.h.
void itk::PowellOptimizer::Swap | ( | double * | a, |
double * | b | ||
) | const [protected] |
Used in bracketing the extreme along the current line. Adapted from NRC
bool itk::PowellOptimizer::m_CatchGetValueException [private] |
Definition at line 234 of file itkPowellOptimizer.h.
Internal storage for the value type / used as a cache
Definition at line 250 of file itkPowellOptimizer.h.
unsigned int itk::PowellOptimizer::m_CurrentIteration [private] |
Current iteration
Definition at line 227 of file itkPowellOptimizer.h.
unsigned int itk::PowellOptimizer::m_CurrentLineIteration [private] |
Definition at line 228 of file itkPowellOptimizer.h.
vnl_vector< double > itk::PowellOptimizer::m_LineDirection [private] |
Definition at line 245 of file itkPowellOptimizer.h.
Definition at line 244 of file itkPowellOptimizer.h.
bool itk::PowellOptimizer::m_Maximize [private] |
Set if the Metric should be maximized: Default = False
Definition at line 238 of file itkPowellOptimizer.h.
unsigned int itk::PowellOptimizer::m_MaximumIteration [private] |
Maximum iteration limit.
Definition at line 231 of file itkPowellOptimizer.h.
unsigned int itk::PowellOptimizer::m_MaximumLineIteration [private] |
Definition at line 232 of file itkPowellOptimizer.h.
double itk::PowellOptimizer::m_MetricWorstPossibleValue [private] |
Definition at line 235 of file itkPowellOptimizer.h.
unsigned int itk::PowellOptimizer::m_SpaceDimension [private] |
Definition at line 222 of file itkPowellOptimizer.h.
double itk::PowellOptimizer::m_StepLength [private] |
The minimal size of search
Definition at line 241 of file itkPowellOptimizer.h.
double itk::PowellOptimizer::m_StepTolerance [private] |
Definition at line 242 of file itkPowellOptimizer.h.
bool itk::PowellOptimizer::m_Stop [private] |
this is user-settable flag to stop optimization. when users call StartOptimization, this value will be set false. By calling StopOptimization, this flag will be set true, and optimization will stop at the next iteration.
Definition at line 256 of file itkPowellOptimizer.h.
std::ostringstream itk::PowellOptimizer::m_StopConditionDescription [private] |
Definition at line 258 of file itkPowellOptimizer.h.
double itk::PowellOptimizer::m_ValueTolerance [private] |
Definition at line 247 of file itkPowellOptimizer.h.