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/*=========================================================================
Program: Insight Segmentation & Registration Toolkit
Module: $RCSfile: itkQuaternionRigidTransformGradientDescentOptimizer.h,v $
Language: C++
Date: $Date: 2007-03-22 14:29:14 $
Version: $Revision: 1.14 $
Copyright (c) Insight Software Consortium. All rights reserved.
See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notices for more information.
=========================================================================*/
#ifndef __itkQuaternionRigidTransformGradientDescentOptimizer_h
#define __itkQuaternionRigidTransformGradientDescentOptimizer_h
#include "itkGradientDescentOptimizer.h"
namespace itk
{
/** \class QuaternionRigidTransformGradientDescentOptimizer
* \brief Implement a gradient descent optimizer
*
* QuaternionRigidTransformGradientDescentOptimizer is an extension to the
* simple gradient descent optimizer implmented in GradientDescentOptimizer.
* At each iteration the current position is updated according to
*
* p(n+1) = p(n) + learningRate * d f(p(n)) / d p(n)
*
* \f[
* p_{n+1} = p_n
* + \mbox{learningRate}
* \, \frac{\partial f(p_n) }{\partial p_n}
* \f]
*
* The learning rate is a fixed scalar defined via SetLearningRate().
* The optimizer steps through a user defined number of iterations;
* no convergence checking is done.
* The first four components of p are assumed to be the four components
* of the quaternion. After each update, the quaternion is normalized to
* have a magnitude of one. This ensures the the transform is purely rigid.
*
* \sa GradientDescentOptimizer
* \ingroup Numerics Optimizers
*/
class ITK_EXPORT QuaternionRigidTransformGradientDescentOptimizer :
public GradientDescentOptimizer
{
public:
/** Standard class typedefs. */
typedef QuaternionRigidTransformGradientDescentOptimizer Self;
typedef GradientDescentOptimizer Superclass;
typedef SmartPointer<Self> Pointer;
typedef SmartPointer<const Self> ConstPointer;
/** Method for creation through the object factory. */
itkNewMacro(Self);
/** Run-time type information (and related methods). */
itkTypeMacro( QuaternionRigidTransformGradientDescentOptimizer,
GradientDescentOptimizer );
/** Parameters type.
* It defines a position in the optimization search space. */
typedef Superclass::ParametersType ParametersType;
/** Advance one step following the gradient direction. */
virtual void AdvanceOneStep( void );
protected:
QuaternionRigidTransformGradientDescentOptimizer() {};
virtual ~QuaternionRigidTransformGradientDescentOptimizer() {};
private:
QuaternionRigidTransformGradientDescentOptimizer(const Self&); //purposely not implemented
void operator=(const Self&); //purposely not implemented
};
} // end namespace itk
#endif
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