ITK  6.0.0
Insight Toolkit
itkGaussianKernelFunction.h
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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 * https://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.
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17 *=========================================================================*/
18#ifndef itkGaussianKernelFunction_h
19#define itkGaussianKernelFunction_h
20
22#include "itkMath.h"
23#include <cmath>
24
25namespace itk
26{
40template <typename TRealValueType = double>
41class ITK_TEMPLATE_EXPORT GaussianKernelFunction : public KernelFunctionBase<TRealValueType>
42{
43public:
44 ITK_DISALLOW_COPY_AND_MOVE(GaussianKernelFunction);
45
50
51 using typename Superclass::RealType;
53 itkNewMacro(Self);
54
56 itkOverrideGetNameOfClassMacro(GaussianKernelFunction);
57
59 TRealValueType
60 Evaluate(const TRealValueType & u) const override
61 {
62 return (std::exp(TRealValueType{ -0.5 } * itk::Math::sqr(u)) * m_Factor);
63 }
66protected:
68 : m_Factor(TRealValueType{ 1.0 } / std::sqrt(TRealValueType{ 2.0 * itk::Math::pi }))
69 {}
70 ~GaussianKernelFunction() override = default;
71 void
72 PrintSelf(std::ostream & os, Indent indent) const override
73 {
74 Superclass::PrintSelf(os, indent);
75 }
76
77private:
78 const TRealValueType m_Factor{};
79};
80} // end namespace itk
81
82#endif
Gaussian kernel used for density estimation and nonparametric regression.
void PrintSelf(std::ostream &os, Indent indent) const override
TRealValueType Evaluate(const TRealValueType &u) const override
~GaussianKernelFunction() override=default
Control indentation during Print() invocation.
Definition: itkIndent.h:50
Kernel used for density estimation and nonparametric regression.
static constexpr double pi
Definition: itkMath.h:66
The "itk" namespace contains all Insight Segmentation and Registration Toolkit (ITK) classes....
STL namespace.