NumCpp  2.10.1
A Templatized Header Only C++ Implementation of the Python NumPy Library
discrete.hpp
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1 #pragma once
29 
30 #include <algorithm>
31 #include <random>
32 
35 #include "NumCpp/Core/Shape.hpp"
36 #include "NumCpp/NdArray.hpp"
38 
39 namespace nc::random
40 {
41  namespace detail
42  {
43  //============================================================================
44  // Method Description:
54  template<typename dtype, typename GeneratorType = std::mt19937>
55  dtype discrete(GeneratorType& generator, const NdArray<double>& inWeights)
56  {
57  STATIC_ASSERT_INTEGER(dtype);
58 
59  std::discrete_distribution<dtype> dist(inWeights.cbegin(), inWeights.cend());
60  return dist(generator);
61  }
62 
63  //============================================================================
64  // Method Description:
76  template<typename dtype, typename GeneratorType = std::mt19937>
77  NdArray<dtype> discrete(GeneratorType& generator, const Shape& inShape, const NdArray<double>& inWeights)
78  {
79  STATIC_ASSERT_INTEGER(dtype);
80 
81  NdArray<dtype> returnArray(inShape);
82 
83  std::discrete_distribution<dtype> dist(inWeights.cbegin(), inWeights.cend());
84 
85  std::for_each(returnArray.begin(),
86  returnArray.end(),
87  [&generator, &dist](dtype& value) -> void { value = dist(generator); });
88 
89  return returnArray;
90  }
91  } // namespace detail
92 
93  //============================================================================
94  // Method Description:
103  template<typename dtype>
104  dtype discrete(const NdArray<double>& inWeights)
105  {
106  return detail::discrete<dtype>(generator_, inWeights);
107  }
108 
109  //============================================================================
110  // Method Description:
121  template<typename dtype>
122  NdArray<dtype> discrete(const Shape& inShape, const NdArray<double>& inWeights)
123  {
124  return detail::discrete<dtype>(generator_, inShape, inWeights);
125  }
126 } // namespace nc::random
#define STATIC_ASSERT_INTEGER(dtype)
Definition: StaticAsserts.hpp:43
const_iterator cbegin() const noexcept
Definition: NdArrayCore.hpp:1308
iterator end() noexcept
Definition: NdArrayCore.hpp:1566
const_iterator cend() const noexcept
Definition: NdArrayCore.hpp:1616
iterator begin() noexcept
Definition: NdArrayCore.hpp:1258
A Shape Class for NdArrays.
Definition: Core/Shape.hpp:41
dtype discrete(GeneratorType &generator, const NdArray< double > &inWeights)
Definition: discrete.hpp:55
Definition: Random/bernoulli.hpp:41
dtype discrete(const NdArray< double > &inWeights)
Definition: discrete.hpp:104
static std::mt19937_64 generator_
generator function
Definition: generator.hpp:35
void for_each(InputIt first, InputIt last, UnaryFunction f)
Definition: StlAlgorithms.hpp:225