00001 /*========================================================================= 00002 00003 Program: Insight Segmentation & Registration Toolkit 00004 Module: $RCSfile: itkRegularizedHeavisideStepFunction.h,v $ 00005 Language: C++ 00006 Date: $Date: 2009-05-09 21:06:28 $ 00007 Version: $Revision: 1.1 $ 00008 00009 Copyright (c) Insight Software Consortium. All rights reserved. 00010 See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details. 00011 00012 This software is distributed WITHOUT ANY WARRANTY; without even 00013 the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 00014 PURPOSE. See the above copyright notices for more information. 00015 00016 =========================================================================*/ 00017 00018 #ifndef __itkRegularizedHeavisideStepFunction_h 00019 #define __itkRegularizedHeavisideStepFunction_h 00020 00021 #include "itkHeavisideStepFunctionBase.h" 00022 #include "itkNumericTraits.h" 00023 #include "vnl/vnl_math.h" 00024 00025 namespace itk 00026 { 00027 00054 template< class TInput = float, class TOutput = double > 00055 class RegularizedHeavisideStepFunction : public HeavisideStepFunctionBase< TInput, TOutput > 00056 { 00057 public: 00058 typedef RegularizedHeavisideStepFunction Self; 00059 typedef HeavisideStepFunctionBase< TInput, TOutput > Superclass; 00060 typedef SmartPointer<Self> Pointer; 00061 typedef SmartPointer<const Self> ConstPointer; 00062 00063 typedef typename Superclass::InputType InputType; 00064 typedef typename Superclass::OutputType OutputType; 00065 00066 typedef typename NumericTraits< InputType >::RealType RealType; 00067 00069 virtual OutputType Evaluate( const InputType& input ) const = 0; 00070 00072 virtual OutputType EvaluateDerivative( const InputType& input ) const = 0; 00073 00074 void SetEpsilon( const RealType & ieps ) 00075 { 00076 this->m_Epsilon = ieps; 00077 00078 if ( ieps > vnl_math::eps ) 00079 { 00080 m_OneOverEpsilon = 1.0 / ieps; 00081 } 00082 else 00083 { 00084 itkGenericExceptionMacro("ERROR: Epsilon needs to be greater than " << vnl_math::eps ); 00085 } 00086 } 00087 00088 RealType GetEpsilon() const 00089 { 00090 return this->m_Epsilon; 00091 } 00092 00093 RealType GetOneOverEpsilon() const 00094 { 00095 return this->m_OneOverEpsilon; 00096 } 00097 00098 protected: 00099 RegularizedHeavisideStepFunction() 00100 { 00101 this->m_Epsilon = 1.0; 00102 this->m_OneOverEpsilon = 1.0; 00103 } 00104 00105 virtual ~RegularizedHeavisideStepFunction() {} 00106 00107 private: 00108 RegularizedHeavisideStepFunction(const Self& ); //purposely not implemented 00109 void operator=(const Self& ); //purposely not implemented 00110 00111 RealType m_Epsilon; 00112 RealType m_OneOverEpsilon; 00113 }; 00114 00115 } 00116 00117 #endif 00118