NumCpp  2.11.0
A Templatized Header Only C++ Implementation of the Python NumPy Library
stdev.hpp
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1 #pragma once
29 
30 #include <algorithm>
31 #include <cmath>
32 #include <complex>
33 
34 #include "NumCpp/Core/Types.hpp"
36 #include "NumCpp/NdArray.hpp"
37 #include "NumCpp/Utils/sqr.hpp"
38 
39 namespace nc
40 {
41  //============================================================================
42  // Method Description:
51  template<typename dtype>
53  {
55 
56  double meanValue = 0.;
57  double sum = 0.;
58 
59  const auto function = [&sum, &meanValue](dtype value) -> void
60  { sum += utils::sqr(static_cast<double>(value) - meanValue); };
61 
62  switch (inAxis)
63  {
64  case Axis::NONE:
65  {
66  meanValue = mean(inArray, inAxis).item();
67  std::for_each(inArray.cbegin(), inArray.cend(), function);
68 
69  NdArray<double> returnArray = { std::sqrt(sum / inArray.size()) };
70  return returnArray;
71  }
72  case Axis::COL:
73  {
74  NdArray<double> meanValueArray = mean(inArray, inAxis);
75  NdArray<double> returnArray(1, inArray.numRows());
76  for (uint32 row = 0; row < inArray.numRows(); ++row)
77  {
78  meanValue = meanValueArray[row];
79  sum = 0.;
80  std::for_each(inArray.cbegin(row), inArray.cend(row), function);
81 
82  returnArray(0, row) = std::sqrt(sum / inArray.numCols());
83  }
84 
85  return returnArray;
86  }
87  case Axis::ROW:
88  {
89  return stdev(inArray.transpose(), Axis::COL);
90  }
91  default:
92  {
93  THROW_INVALID_ARGUMENT_ERROR("Unimplemented axis type.");
94  return {}; // get rid of compiler warning
95  }
96  }
97  }
98 
99  //============================================================================
100  // Method Description:
109  template<typename dtype>
110  NdArray<std::complex<double>> stdev(const NdArray<std::complex<dtype>>& inArray, Axis inAxis = Axis::NONE)
111  {
113 
114  std::complex<double> meanValue(0., 0.);
115  std::complex<double> sum(0., 0.);
116 
117  const auto function = [&sum, &meanValue](std::complex<dtype> value) -> void
118  { sum += utils::sqr(complex_cast<double>(value) - meanValue); };
119 
120  switch (inAxis)
121  {
122  case Axis::NONE:
123  {
124  meanValue = mean(inArray, inAxis).item();
125  std::for_each(inArray.cbegin(), inArray.cend(), function);
126 
127  NdArray<std::complex<double>> returnArray = { std::sqrt(sum / static_cast<double>(inArray.size())) };
128  return returnArray;
129  }
130  case Axis::COL:
131  {
132  NdArray<std::complex<double>> meanValueArray = mean(inArray, inAxis);
133  NdArray<std::complex<double>> returnArray(1, inArray.numRows());
134  for (uint32 row = 0; row < inArray.numRows(); ++row)
135  {
136  meanValue = meanValueArray[row];
137  sum = std::complex<double>(0., 0.);
138  std::for_each(inArray.cbegin(row), inArray.cend(row), function);
139 
140  returnArray(0, row) = std::sqrt(sum / static_cast<double>(inArray.numCols()));
141  }
142 
143  return returnArray;
144  }
145  case Axis::ROW:
146  {
147  NdArray<std::complex<double>> meanValueArray = mean(inArray, inAxis);
148  NdArray<std::complex<dtype>> transposedArray = inArray.transpose();
149  NdArray<std::complex<double>> returnArray(1, transposedArray.numRows());
150  for (uint32 row = 0; row < transposedArray.numRows(); ++row)
151  {
152  meanValue = meanValueArray[row];
153  sum = std::complex<double>(0., 0.);
154  std::for_each(transposedArray.cbegin(row), transposedArray.cend(row), function);
155 
156  returnArray(0, row) = std::sqrt(sum / static_cast<double>(transposedArray.numCols()));
157  }
158 
159  return returnArray;
160  }
161  default:
162  {
163  THROW_INVALID_ARGUMENT_ERROR("Unimplemented axis type.");
164  return {}; // get rid of compiler warning
165  }
166  }
167  }
168 } // namespace nc
#define THROW_INVALID_ARGUMENT_ERROR(msg)
Definition: Error.hpp:37
#define STATIC_ASSERT_ARITHMETIC(dtype)
Definition: StaticAsserts.hpp:39
size_type size() const noexcept
Definition: NdArrayCore.hpp:4477
const_iterator cbegin() const noexcept
Definition: NdArrayCore.hpp:1318
self_type transpose() const
Definition: NdArrayCore.hpp:4837
size_type numCols() const noexcept
Definition: NdArrayCore.hpp:3418
size_type numRows() const noexcept
Definition: NdArrayCore.hpp:3430
const_iterator cend() const noexcept
Definition: NdArrayCore.hpp:1626
value_type item() const
Definition: NdArrayCore.hpp:2975
void for_each(InputIt first, InputIt last, UnaryFunction f)
Definition: StlAlgorithms.hpp:225
constexpr dtype sqr(dtype inValue) noexcept
Definition: sqr.hpp:42
Definition: Cartesian.hpp:40
Axis
Enum To describe an axis.
Definition: Types.hpp:47
auto sqrt(dtype inValue) noexcept
Definition: sqrt.hpp:48
NdArray< dtype > sum(const NdArray< dtype > &inArray, Axis inAxis=Axis::NONE)
Definition: sum.hpp:46
NdArray< double > stdev(const NdArray< dtype > &inArray, Axis inAxis=Axis::NONE)
Definition: stdev.hpp:52
NdArray< double > mean(const NdArray< dtype > &inArray, Axis inAxis=Axis::NONE)
Definition: mean.hpp:52
std::uint32_t uint32
Definition: Types.hpp:40