Eigen  3.3.0
 
Loading...
Searching...
No Matches
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
13namespace Eigen {
14
15namespace internal {
16
17// default implementation of digits10(), based on numeric_limits if specialized,
18// 0 for integer types, and log10(epsilon()) otherwise.
19template< typename T,
20 bool use_numeric_limits = std::numeric_limits<T>::is_specialized,
21 bool is_integer = NumTraits<T>::IsInteger>
22struct default_digits10_impl
23{
24 static int run() { return std::numeric_limits<T>::digits10; }
25};
26
27template<typename T>
28struct 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
38template<typename T>
39struct default_digits10_impl<T,false,true> // Integer
40{
41 static int run() { return 0; }
42};
43
44} // end namespace internal
45
88template<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,
103 typename internal::conditional<sizeof(T)<=2, float, double>::type,
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 {
118 return internal::default_digits10_impl<T>::run();
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
150template<typename T> struct NumTraits : GenericNumTraits<T>
151{};
152
153template<> struct NumTraits<float>
154 : GenericNumTraits<float>
155{
156 EIGEN_DEVICE_FUNC
157 static inline float dummy_precision() { return 1e-5f; }
158};
159
160template<> struct NumTraits<double> : GenericNumTraits<double>
161{
162 EIGEN_DEVICE_FUNC
163 static inline double dummy_precision() { return 1e-12; }
164};
165
166template<> struct NumTraits<long double>
167 : GenericNumTraits<long double>
168{
169 static inline long double dummy_precision() { return 1e-15l; }
170};
171
172template<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,
182 MulCost = 4 * NumTraits<Real>::MulCost + 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
193template<typename Scalar, int Rows, int Cols, int Options, int MaxRows, int MaxCols>
194struct NumTraits<Array<Scalar, Rows, Cols, Options, MaxRows, MaxCols> >
195{
196 typedef Array<Scalar, Rows, Cols, Options, MaxRows, MaxCols> ArrayType;
197 typedef typename NumTraits<Scalar>::Real RealScalar;
198 typedef Array<RealScalar, Rows, Cols, Options, MaxRows, MaxCols> Real;
199 typedef typename NumTraits<Scalar>::NonInteger NonIntegerScalar;
200 typedef Array<NonIntegerScalar, Rows, Cols, Options, MaxRows, MaxCols> NonInteger;
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
220template<> 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
232private:
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.
242template<> struct NumTraits<void> {};
243
244} // end namespace Eigen
245
246#endif // EIGEN_NUMTRAITS_H
Namespace containing all symbols from the Eigen library.
Definition: Core:287
const int HugeCost
Definition: Constants.h:39
const int Dynamic
Definition: Constants.h:21
Holds information about the various numeric (i.e. scalar) types allowed by Eigen.
Definition: NumTraits.h:151