NumCpp  2.8.0
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 = 0.0;
57  double sum = 0.0;
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 = 0.0;
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  NdArray<double> meanValueArray = mean(inArray, inAxis);
90  NdArray<dtype> transposedArray = inArray.transpose();
91  NdArray<double> returnArray(1, transposedArray.numRows());
92  for (uint32 row = 0; row < transposedArray.numRows(); ++row)
93  {
94  meanValue = meanValueArray[row];
95  sum = 0.0;
96  std::for_each(transposedArray.cbegin(row), transposedArray.cend(row), function);
97 
98  returnArray(0, row) = std::sqrt(sum / transposedArray.numCols());
99  }
100 
101  return returnArray;
102  }
103  default:
104  {
105  THROW_INVALID_ARGUMENT_ERROR("Unimplemented axis type.");
106  return {}; // get rid of compiler warning
107  }
108  }
109  }
110 
111  //============================================================================
112  // Method Description:
121  template<typename dtype>
122  NdArray<std::complex<double>> stdev(const NdArray<std::complex<dtype>>& inArray, Axis inAxis = Axis::NONE)
123  {
125 
126  std::complex<double> meanValue(0.0, 0.0);
127  std::complex<double> sum(0.0, 0.0);
128 
129  const auto function = [&sum, &meanValue](std::complex<dtype> value) -> void
130  { sum += utils::sqr(complex_cast<double>(value) - meanValue); };
131 
132  switch (inAxis)
133  {
134  case Axis::NONE:
135  {
136  meanValue = mean(inArray, inAxis).item();
137  std::for_each(inArray.cbegin(), inArray.cend(), function);
138 
139  NdArray<std::complex<double>> returnArray = { std::sqrt(sum / static_cast<double>(inArray.size())) };
140  return returnArray;
141  }
142  case Axis::COL:
143  {
144  NdArray<std::complex<double>> meanValueArray = mean(inArray, inAxis);
145  NdArray<std::complex<double>> returnArray(1, inArray.numRows());
146  for (uint32 row = 0; row < inArray.numRows(); ++row)
147  {
148  meanValue = meanValueArray[row];
149  sum = std::complex<double>(0.0, 0.0);
150  std::for_each(inArray.cbegin(row), inArray.cend(row), function);
151 
152  returnArray(0, row) = std::sqrt(sum / static_cast<double>(inArray.numCols()));
153  }
154 
155  return returnArray;
156  }
157  case Axis::ROW:
158  {
159  NdArray<std::complex<double>> meanValueArray = mean(inArray, inAxis);
160  NdArray<std::complex<dtype>> transposedArray = inArray.transpose();
161  NdArray<std::complex<double>> returnArray(1, transposedArray.numRows());
162  for (uint32 row = 0; row < transposedArray.numRows(); ++row)
163  {
164  meanValue = meanValueArray[row];
165  sum = std::complex<double>(0.0, 0.0);
166  std::for_each(transposedArray.cbegin(row), transposedArray.cend(row), function);
167 
168  returnArray(0, row) = std::sqrt(sum / static_cast<double>(transposedArray.numCols()));
169  }
170 
171  return returnArray;
172  }
173  default:
174  {
175  THROW_INVALID_ARGUMENT_ERROR("Unimplemented axis type.");
176  return {}; // get rid of compiler warning
177  }
178  }
179  }
180 } // namespace nc
#define THROW_INVALID_ARGUMENT_ERROR(msg)
Definition: Error.hpp:36
#define STATIC_ASSERT_ARITHMETIC(dtype)
Definition: StaticAsserts.hpp:37
uint32 numCols() const noexcept
Definition: NdArrayCore.hpp:3416
size_type size() const noexcept
Definition: NdArrayCore.hpp:4289
const_iterator cbegin() const noexcept
Definition: NdArrayCore.hpp:1221
uint32 numRows() const noexcept
Definition: NdArrayCore.hpp:3428
NdArray< dtype > transpose() const
Definition: NdArrayCore.hpp:4650
const_iterator cend() const noexcept
Definition: NdArrayCore.hpp:1529
value_type item() const
Definition: NdArrayCore.hpp:2921
void for_each(InputIt first, InputIt last, UnaryFunction f)
Definition: StlAlgorithms.hpp:227
constexpr dtype sqr(dtype inValue) noexcept
Definition: sqr.hpp:44
Definition: Coordinate.hpp:45
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