NumCpp  2.11.0
A Templatized Header Only C++ Implementation of the Python NumPy Library
nonCentralChiSquared.hpp
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1 #pragma once
29 
30 #ifndef NUMCPP_NO_USE_BOOST
31 
32 #include <algorithm>
33 #include <string>
34 
35 #include "boost/random/non_central_chi_squared_distribution.hpp"
36 
39 #include "NumCpp/Core/Shape.hpp"
40 #include "NumCpp/NdArray.hpp"
42 
43 namespace nc::random
44 {
45  namespace detail
46  {
47  //============================================================================
48  // Method Description:
60  template<typename dtype, typename GeneratorType = std::mt19937>
61  dtype nonCentralChiSquared(GeneratorType& generator, dtype inK = 1, dtype inLambda = 1)
62  {
64 
65  if (inK <= 0)
66  {
67  THROW_INVALID_ARGUMENT_ERROR("input k must be greater than zero.");
68  }
69 
70  if (inLambda <= 0)
71  {
72  THROW_INVALID_ARGUMENT_ERROR("input lambda must be greater than zero.");
73  }
74 
75  boost::random::non_central_chi_squared_distribution<dtype> dist(inK, inLambda);
76  return dist(generator);
77  }
78 
79  //============================================================================
80  // Method Description:
94  template<typename dtype, typename GeneratorType = std::mt19937>
96  nonCentralChiSquared(GeneratorType& generator, const Shape& inShape, dtype inK = 1, dtype inLambda = 1)
97  {
99 
100  if (inK <= 0)
101  {
102  THROW_INVALID_ARGUMENT_ERROR("input k must be greater than zero.");
103  }
104 
105  if (inLambda <= 0)
106  {
107  THROW_INVALID_ARGUMENT_ERROR("input lambda must be greater than zero.");
108  }
109 
110  NdArray<dtype> returnArray(inShape);
111 
112  boost::random::non_central_chi_squared_distribution<dtype> dist(inK, inLambda);
113 
114  std::for_each(returnArray.begin(),
115  returnArray.end(),
116  [&generator, &dist](dtype& value) -> void { value = dist(generator); });
117 
118  return returnArray;
119  }
120  } // namespace detail
121 
122  //============================================================================
123  // Method Description:
134  template<typename dtype>
135  dtype nonCentralChiSquared(dtype inK = 1, dtype inLambda = 1)
136  {
137  return detail::nonCentralChiSquared(generator_, inK, inLambda);
138  }
139 
140  //============================================================================
141  // Method Description:
154  template<typename dtype>
155  NdArray<dtype> nonCentralChiSquared(const Shape& inShape, dtype inK = 1, dtype inLambda = 1)
156  {
157  return detail::nonCentralChiSquared(generator_, inShape, inK, inLambda);
158  }
159 } // namespace nc::random
160 
161 #endif // #ifndef NUMCPP_NO_USE_BOOST
#define THROW_INVALID_ARGUMENT_ERROR(msg)
Definition: Error.hpp:37
#define STATIC_ASSERT_ARITHMETIC(dtype)
Definition: StaticAsserts.hpp:39
Holds 1D and 2D arrays, the main work horse of the NumCpp library.
Definition: NdArrayCore.hpp:138
iterator end() noexcept
Definition: NdArrayCore.hpp:1576
iterator begin() noexcept
Definition: NdArrayCore.hpp:1268
A Shape Class for NdArrays.
Definition: Core/Shape.hpp:41
dtype nonCentralChiSquared(GeneratorType &generator, dtype inK=1, dtype inLambda=1)
Definition: nonCentralChiSquared.hpp:61
Definition: Random/bernoulli.hpp:41
static std::mt19937_64 generator_
generator function
Definition: generator.hpp:35
dtype nonCentralChiSquared(dtype inK=1, dtype inLambda=1)
Definition: nonCentralChiSquared.hpp:135
void for_each(InputIt first, InputIt last, UnaryFunction f)
Definition: StlAlgorithms.hpp:225