ITK  5.2.0
Insight Toolkit
itkGaussianKernelFunction.h
Go to the documentation of this file.
1 /*=========================================================================
2  *
3  * Copyright NumFOCUS
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0.txt
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  *
17  *=========================================================================*/
18 #ifndef itkGaussianKernelFunction_h
19 #define itkGaussianKernelFunction_h
20 
21 #include "itkKernelFunctionBase.h"
22 #include "itkMath.h"
23 #include <cmath>
24 
25 namespace itk
26 {
40 template <typename TRealValueType = double>
41 class GaussianKernelFunction : public KernelFunctionBase<TRealValueType>
42 {
43 public:
44  ITK_DISALLOW_COPY_AND_ASSIGN(GaussianKernelFunction);
45 
50 
51  using RealType = typename Superclass::RealType;
53  itkNewMacro(Self);
54 
57 
59  TRealValueType
60  Evaluate(const TRealValueType & u) const override
61  {
62  return (std::exp(static_cast<TRealValueType>(-0.5) * itk::Math::sqr(u)) * m_Factor);
63  }
64 
65 protected:
67  : m_Factor(NumericTraits<TRealValueType>::OneValue() /
68  std::sqrt(static_cast<TRealValueType>(2.0 * itk::Math::pi))){};
69  ~GaussianKernelFunction() override = default;
70  void
71  PrintSelf(std::ostream & os, Indent indent) const override
72  {
73  Superclass::PrintSelf(os, indent);
74  }
75 
76 private:
77  const TRealValueType m_Factor;
78 };
79 } // end namespace itk
80 
81 #endif
itk::GaussianKernelFunction::~GaussianKernelFunction
~GaussianKernelFunction() override=default
itk::KernelFunctionBase::RealType
TRealValueType RealType
Definition: itkKernelFunctionBase.h:52
itk::GaussianKernelFunction< double >::RealType
typename Superclass::RealType RealType
Definition: itkGaussianKernelFunction.h:51
itk::GaussianKernelFunction
Gaussian kernel used for density estimation and nonparametric regression.
Definition: itkGaussianKernelFunction.h:41
itk::GaussianKernelFunction::m_Factor
const TRealValueType m_Factor
Definition: itkGaussianKernelFunction.h:77
itk::KernelFunctionBase
Kernel used for density estimation and nonparametric regression.
Definition: itkKernelFunctionBase.h:43
itkKernelFunctionBase.h
itk::SmartPointer< Self >
itk::Indent
Control indentation during Print() invocation.
Definition: itkIndent.h:49
itk::GaussianKernelFunction::GaussianKernelFunction
GaussianKernelFunction()
Definition: itkGaussianKernelFunction.h:66
itk::GaussianKernelFunction::PrintSelf
void PrintSelf(std::ostream &os, Indent indent) const override
Definition: itkGaussianKernelFunction.h:71
itk::LightObject
Light weight base class for most itk classes.
Definition: itkLightObject.h:59
itk::KernelFunctionBase::PrintSelf
void PrintSelf(std::ostream &os, Indent indent) const override
Definition: itkKernelFunctionBase.h:71
itk::NumericTraits
Define additional traits for native types such as int or float.
Definition: itkNumericTraits.h:58
itk
The "itk" namespace contains all Insight Segmentation and Registration Toolkit (ITK) classes....
Definition: itkAnnulusOperator.h:24
itk::GaussianKernelFunction::Evaluate
TRealValueType Evaluate(const TRealValueType &u) const override
Definition: itkGaussianKernelFunction.h:60
itk::Math::pi
static constexpr double pi
Definition: itkMath.h:64
itkMath.h