compbio
NumTraits.h
1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2006-2010 Benoit Jacob <jacob.benoit.1@gmail.com>
5 //
6 // This Source Code Form is subject to the terms of the Mozilla
7 // Public License v. 2.0. If a copy of the MPL was not distributed
8 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
9 
10 #ifndef EIGEN_NUMTRAITS_H
11 #define EIGEN_NUMTRAITS_H
12 
13 namespace Eigen {
14 
15 namespace internal {
16 
17 // default implementation of digits10(), based on numeric_limits if specialized,
18 // 0 for integer types, and log10(epsilon()) otherwise.
19 template< typename T,
20  bool use_numeric_limits = std::numeric_limits<T>::is_specialized,
21  bool is_integer = NumTraits<T>::IsInteger>
23 {
24  static int run() { return std::numeric_limits<T>::digits10; }
25 };
26 
27 template<typename T>
28 struct default_digits10_impl<T,false,false> // Floating point
29 {
30  static int run() {
31  using std::log10;
32  using std::ceil;
33  typedef typename NumTraits<T>::Real Real;
34  return int(ceil(-log10(NumTraits<Real>::epsilon())));
35  }
36 };
37 
38 template<typename T>
39 struct default_digits10_impl<T,false,true> // Integer
40 {
41  static int run() { return 0; }
42 };
43 
44 } // end namespace internal
45 
88 template<typename T> struct GenericNumTraits
89 {
90  enum {
91  IsInteger = std::numeric_limits<T>::is_integer,
92  IsSigned = std::numeric_limits<T>::is_signed,
93  IsComplex = 0,
94  RequireInitialization = internal::is_arithmetic<T>::value ? 0 : 1,
95  ReadCost = 1,
96  AddCost = 1,
97  MulCost = 1
98  };
99 
100  typedef T Real;
101  typedef typename internal::conditional<
102  IsInteger,
104  T
105  >::type NonInteger;
106  typedef T Nested;
107  typedef T Literal;
108 
109  EIGEN_DEVICE_FUNC
110  static inline Real epsilon()
111  {
112  return numext::numeric_limits<T>::epsilon();
113  }
114 
115  EIGEN_DEVICE_FUNC
116  static inline int digits10()
117  {
119  }
120 
121  EIGEN_DEVICE_FUNC
122  static inline Real dummy_precision()
123  {
124  // make sure to override this for floating-point types
125  return Real(0);
126  }
127 
128 
129  EIGEN_DEVICE_FUNC
130  static inline T highest() {
131  return (numext::numeric_limits<T>::max)();
132  }
133 
134  EIGEN_DEVICE_FUNC
135  static inline T lowest() {
136  return IsInteger ? (numext::numeric_limits<T>::min)() : (-(numext::numeric_limits<T>::max)());
137  }
138 
139  EIGEN_DEVICE_FUNC
140  static inline T infinity() {
141  return numext::numeric_limits<T>::infinity();
142  }
143 
144  EIGEN_DEVICE_FUNC
145  static inline T quiet_NaN() {
146  return numext::numeric_limits<T>::quiet_NaN();
147  }
148 };
149 
150 template<typename T> struct NumTraits : GenericNumTraits<T>
151 {};
152 
153 template<> struct NumTraits<float>
154  : GenericNumTraits<float>
155 {
156  EIGEN_DEVICE_FUNC
157  static inline float dummy_precision() { return 1e-5f; }
158 };
159 
160 template<> struct NumTraits<double> : GenericNumTraits<double>
161 {
162  EIGEN_DEVICE_FUNC
163  static inline double dummy_precision() { return 1e-12; }
164 };
165 
166 template<> struct NumTraits<long double>
167  : GenericNumTraits<long double>
168 {
169  static inline long double dummy_precision() { return 1e-15l; }
170 };
171 
172 template<typename _Real> struct NumTraits<std::complex<_Real> >
173  : GenericNumTraits<std::complex<_Real> >
174 {
175  typedef _Real Real;
176  typedef typename NumTraits<_Real>::Literal Literal;
177  enum {
178  IsComplex = 1,
179  RequireInitialization = NumTraits<_Real>::RequireInitialization,
180  ReadCost = 2 * NumTraits<_Real>::ReadCost,
181  AddCost = 2 * NumTraits<Real>::AddCost,
183  };
184 
185  EIGEN_DEVICE_FUNC
186  static inline Real epsilon() { return NumTraits<Real>::epsilon(); }
187  EIGEN_DEVICE_FUNC
188  static inline Real dummy_precision() { return NumTraits<Real>::dummy_precision(); }
189  EIGEN_DEVICE_FUNC
190  static inline int digits10() { return NumTraits<Real>::digits10(); }
191 };
192 
193 template<typename Scalar, int Rows, int Cols, int Options, int MaxRows, int MaxCols>
194 struct NumTraits<Array<Scalar, Rows, Cols, Options, MaxRows, MaxCols> >
195 {
197  typedef typename NumTraits<Scalar>::Real RealScalar;
199  typedef typename NumTraits<Scalar>::NonInteger NonIntegerScalar;
201  typedef ArrayType & Nested;
202  typedef typename NumTraits<Scalar>::Literal Literal;
203 
204  enum {
205  IsComplex = NumTraits<Scalar>::IsComplex,
206  IsInteger = NumTraits<Scalar>::IsInteger,
207  IsSigned = NumTraits<Scalar>::IsSigned,
208  RequireInitialization = 1,
209  ReadCost = ArrayType::SizeAtCompileTime==Dynamic ? HugeCost : ArrayType::SizeAtCompileTime * NumTraits<Scalar>::ReadCost,
210  AddCost = ArrayType::SizeAtCompileTime==Dynamic ? HugeCost : ArrayType::SizeAtCompileTime * NumTraits<Scalar>::AddCost,
211  MulCost = ArrayType::SizeAtCompileTime==Dynamic ? HugeCost : ArrayType::SizeAtCompileTime * NumTraits<Scalar>::MulCost
212  };
213 
214  EIGEN_DEVICE_FUNC
215  static inline RealScalar epsilon() { return NumTraits<RealScalar>::epsilon(); }
216  EIGEN_DEVICE_FUNC
217  static inline RealScalar dummy_precision() { return NumTraits<RealScalar>::dummy_precision(); }
218 };
219 
220 template<> struct NumTraits<std::string>
221  : GenericNumTraits<std::string>
222 {
223  enum {
224  RequireInitialization = 1,
225  ReadCost = HugeCost,
226  AddCost = HugeCost,
227  MulCost = HugeCost
228  };
229 
230  static inline int digits10() { return 0; }
231 
232 private:
233  static inline std::string epsilon();
234  static inline std::string dummy_precision();
235  static inline std::string lowest();
236  static inline std::string highest();
237  static inline std::string infinity();
238  static inline std::string quiet_NaN();
239 };
240 
241 // Empty specialization for void to allow template specialization based on NumTraits<T>::Real with T==void and SFINAE.
242 template<> struct NumTraits<void> {};
243 
244 } // end namespace Eigen
245 
246 #endif // EIGEN_NUMTRAITS_H
Definition: NumTraits.h:88
const int HugeCost
This value means that the cost to evaluate an expression coefficient is either very expensive or cann...
Definition: Constants.h:39
Namespace containing all symbols from the Eigen library.
Definition: bench_norm.cpp:85
Definition: Half.h:529
Holds information about the various numeric (i.e.
Definition: NumTraits.h:150
Definition: Meta.h:58
Definition: NumTraits.h:22
Definition: Meta.h:85
Definition: BandTriangularSolver.h:13
General-purpose arrays with easy API for coefficient-wise operations.
Definition: Array.h:45
Definition: datatypes.h:12
const int Dynamic
This value means that a positive quantity (e.g., a size) is not known at compile-time, and that instead the value is stored in some runtime variable.
Definition: Constants.h:21