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itk::ExhaustiveOptimizer Class Reference
[Numerics, Optimizers]
Optimizer that fully samples a grid on the parametric space.
More...
#include <itkExhaustiveOptimizer.h>
Inheritance diagram for itk::ExhaustiveOptimizer:
[legend]Collaboration diagram for itk::ExhaustiveOptimizer:
[legend]List of all members.
Detailed Description
Optimizer that fully samples a grid on the parametric space.
This optimizer is equivalent to an exahaustive search in a discrete grid defined over the parametric space. The grid parameters are define through an array of minimum and maximum values. The subdivisions of the grid along each one of the dimensions of the parametric space is defined by an array of number of steps. This optimizer is useful when its needed to plot the entire metric space to get an idea of how noisy it is etc...
A typical use of the optimizer is to plot the metric space to get an idea of how noisy it is. An example is given below, where it is desired to plot the metric space with respect to translations along x, y and z in a 3D registration application: Here it is assumed that the transform is Euler3DTransform.
OptimizerType::StepsType steps( m_Transform->GetNumberOfParameters() );
steps[1] = 0;
steps[2] = 0;
steps[3] = 0;
steps[3] = 10;
steps[4] = 10;
steps[5] = 10;
m_Optimizer->SetNumberOfSteps( steps );
m_Optimizer->SetStepLength( 2 );
The optimizer throws IterationEvents after every iteration. We use this to plot the metric space in an image as follows:
if( itk::IterationEvent().CheckEvent(& event ) )
{
IndexType index;
index[0] = m_Optimizer->GetCurrentIndex()[3];
index[1] = m_Optimizer->GetCurrentIndex()[1];
index[2] = m_Optimizer->GetCurrentIndex()[2];
image->SetPixel( index, m_Optimizer->GetCurrentValue() );
}
The image size is expected to be 21 x 21 x 21 with a spacing of 2.
If you wish to use different step lengths along each parametric axis, you can use the SetScales() method. This accepts an array, each element represents the number of subdivisions per step length. For instance scales of [0 0 0 0.5 1 4 ] along with a step length of 2 will cause the optimizer to search the metric space on a grid with x,y,z spacing of [1 2 8].
Definition at line 81 of file itkExhaustiveOptimizer.h.
Member Typedef Documentation
Constructor & Destructor Documentation
| itk::ExhaustiveOptimizer::ExhaustiveOptimizer |
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Member Function Documentation
| void itk::ExhaustiveOptimizer::AdvanceOneStep |
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Advance one step following the gradient direction This method verifies if a change in direction is required and if a reduction in steplength is required. |
| virtual const ParametersType& itk::ExhaustiveOptimizer::GetCurrentIndex |
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| virtual const MeasureType& itk::ExhaustiveOptimizer::GetCurrentValue |
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| virtual const MeasureType& itk::ExhaustiveOptimizer::GetMaximumMetricValue |
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| virtual const ParametersType& itk::ExhaustiveOptimizer::GetMaximumMetricValuePosition |
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| virtual const unsigned long& itk::ExhaustiveOptimizer::GetMaximumNumberOfIterations |
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| virtual const MeasureType& itk::ExhaustiveOptimizer::GetMinimumMetricValue |
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| virtual const ParametersType& itk::ExhaustiveOptimizer::GetMinimumMetricValuePosition |
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| virtual const char* itk::ExhaustiveOptimizer::GetNameOfClass |
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| virtual const StepsType& itk::ExhaustiveOptimizer::GetNumberOfSteps |
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| virtual const double& itk::ExhaustiveOptimizer::GetStepLength |
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| void itk::ExhaustiveOptimizer::IncrementIndex |
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ParametersType & |
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Advance one step following the gradient direction This method verifies if a change in direction is required and if a reduction in steplength is required. |
| Pointer itk::ExhaustiveOptimizer::New |
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| void itk::ExhaustiveOptimizer::PrintSelf |
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std::ostream & |
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Indent |
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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::SingleValuedNonLinearOptimizer. |
| void itk::ExhaustiveOptimizer::ResumeWalking |
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| virtual void itk::ExhaustiveOptimizer::SetNumberOfSteps |
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StepsType |
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| virtual void itk::ExhaustiveOptimizer::SetStepLength |
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double |
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| virtual void itk::ExhaustiveOptimizer::StartOptimization |
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| void itk::ExhaustiveOptimizer::StartWalking |
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| void itk::ExhaustiveOptimizer::StopWalking |
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Member Data Documentation
The documentation for this class was generated from the following file:
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