NumCpp  2.10.1
A Templatized Header Only C++ Implementation of the Python NumPy Library
Random/beta.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/beta_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 beta(GeneratorType& generator, dtype inAlpha, dtype inBeta)
62  {
64 
65  if (inAlpha < 0)
66  {
67  THROW_INVALID_ARGUMENT_ERROR("input alpha must be greater than zero.");
68  }
69 
70  if (inBeta < 0)
71  {
72  THROW_INVALID_ARGUMENT_ERROR("input beta must be greater than zero.");
73  }
74 
75  boost::random::beta_distribution<dtype> dist(inAlpha, inBeta);
76  return dist(generator);
77  }
78 
79  //============================================================================
80  // Method Description:
94  template<typename dtype, typename GeneratorType = std::mt19937>
95  NdArray<dtype> beta(GeneratorType& generator, const Shape& inShape, dtype inAlpha, dtype inBeta)
96  {
98 
99  if (inAlpha < 0)
100  {
101  THROW_INVALID_ARGUMENT_ERROR("input alpha must be greater than zero.");
102  }
103 
104  if (inBeta < 0)
105  {
106  THROW_INVALID_ARGUMENT_ERROR("input beta must be greater than zero.");
107  }
108 
109  NdArray<dtype> returnArray(inShape);
110 
111  boost::random::beta_distribution<dtype> dist(inAlpha, inBeta);
112 
113  std::for_each(returnArray.begin(),
114  returnArray.end(),
115  [&generator, &dist](dtype& value) -> void { value = dist(generator); });
116 
117  return returnArray;
118  }
119  } // namespace detail
120 
121  //============================================================================
122  // Method Description:
133  template<typename dtype>
134  dtype beta(dtype inAlpha, dtype inBeta)
135  {
136  return detail::beta(generator_, inAlpha, inBeta);
137  }
138 
139  //============================================================================
140  // Method Description:
153  template<typename dtype>
154  NdArray<dtype> beta(const Shape& inShape, dtype inAlpha, dtype inBeta)
155  {
156  return detail::beta(generator_, inShape, inAlpha, inBeta);
157  }
158 } // namespace nc::random
159 
160 #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:1566
iterator begin() noexcept
Definition: NdArrayCore.hpp:1258
A Shape Class for NdArrays.
Definition: Core/Shape.hpp:41
dtype beta(GeneratorType &generator, dtype inAlpha, dtype inBeta)
Definition: Random/beta.hpp:61
Definition: Random/bernoulli.hpp:41
dtype beta(dtype inAlpha, dtype inBeta)
Definition: Random/beta.hpp:134
static std::mt19937_64 generator_
generator function
Definition: generator.hpp:35
void for_each(InputIt first, InputIt last, UnaryFunction f)
Definition: StlAlgorithms.hpp:225