NumCpp  2.9.0
A Templatized Header Only C++ Implementation of the Python NumPy Library
trim_zeros.hpp
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1 #pragma once
29 
30 #include <string>
31 
35 #include "NumCpp/Core/Types.hpp"
36 #include "NumCpp/NdArray.hpp"
37 
38 namespace nc
39 {
40  //============================================================================
41  // Method Description:
51  template<typename dtype>
52  NdArray<dtype> trim_zeros(const NdArray<dtype>& inArray, const std::string& inTrim = "fb")
53  {
55 
56  if (inTrim == "f")
57  {
58  uint32 place = 0;
59  for (auto value : inArray)
60  {
61  if (value != dtype{ 0 })
62  {
63  break;
64  }
65 
66  ++place;
67  }
68 
69  if (place == inArray.size())
70  {
71  return NdArray<dtype>(0);
72  }
73 
74  NdArray<dtype> returnArray(1, inArray.size() - place);
75  stl_algorithms::copy(inArray.cbegin() + place, inArray.cend(), returnArray.begin());
76 
77  return returnArray;
78  }
79 
80  if (inTrim == "b")
81  {
82  uint32 place = inArray.size();
83  for (uint32 i = inArray.size() - 1; i > 0; --i)
84  {
85  if (inArray[i] != dtype{ 0 })
86  {
87  break;
88  }
89 
90  --place;
91  }
92 
93  if (place == 0 || (place == 1 && inArray[0] == dtype{ 0 }))
94  {
95  return NdArray<dtype>(0);
96  }
97 
98  NdArray<dtype> returnArray(1, place);
99  stl_algorithms::copy(inArray.cbegin(), inArray.cbegin() + place, returnArray.begin());
100 
101  return returnArray;
102  }
103 
104  if (inTrim == "fb")
105  {
106  uint32 placeBegin = 0;
107  for (auto value : inArray)
108  {
109  if (value != dtype{ 0 })
110  {
111  break;
112  }
113 
114  ++placeBegin;
115  }
116 
117  if (placeBegin == inArray.size())
118  {
119  return NdArray<dtype>(0);
120  }
121 
122  uint32 placeEnd = inArray.size();
123  for (uint32 i = inArray.size() - 1; i > 0; --i)
124  {
125  if (inArray[i] != dtype{ 0 })
126  {
127  break;
128  }
129 
130  --placeEnd;
131  }
132 
133  if (placeEnd == 0 || (placeEnd == 1 && inArray[0] == dtype{ 0 }))
134  {
135  return NdArray<dtype>(0);
136  }
137 
138  NdArray<dtype> returnArray(1, placeEnd - placeBegin);
139  stl_algorithms::copy(inArray.cbegin() + placeBegin, inArray.cbegin() + placeEnd, returnArray.begin());
140 
141  return returnArray;
142  }
143 
144  THROW_INVALID_ARGUMENT_ERROR("trim options are 'f' = front, 'b' = back, 'fb' = front and back.");
145  return {};
146  }
147 } // namespace nc
#define THROW_INVALID_ARGUMENT_ERROR(msg)
Definition: Error.hpp:36
#define STATIC_ASSERT_ARITHMETIC_OR_COMPLEX(dtype)
Definition: StaticAsserts.hpp:49
Holds 1D and 2D arrays, the main work horse of the NumCpp library.
Definition: NdArrayCore.hpp:72
size_type size() const noexcept
Definition: NdArrayCore.hpp:4105
const_iterator cbegin() const noexcept
Definition: NdArrayCore.hpp:1221
iterator begin() noexcept
Definition: NdArrayCore.hpp:1171
OutputIt copy(InputIt first, InputIt last, OutputIt destination) noexcept
Definition: StlAlgorithms.hpp:99
Definition: Coordinate.hpp:45
void place(NdArray< dtype > &arr, const NdArray< bool > &mask, const NdArray< dtype > &vals)
Definition: place.hpp:48
NdArray< dtype > trim_zeros(const NdArray< dtype > &inArray, const std::string &inTrim="fb")
Definition: trim_zeros.hpp:52
std::uint32_t uint32
Definition: Types.hpp:40