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GMath.hpp
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1 /***************************************************************************
2  * GMath.hpp - Mathematical functions *
3  * ----------------------------------------------------------------------- *
4  * copyright (C) 2012-2018 by Juergen Knoedlseder *
5  * ----------------------------------------------------------------------- *
6  * *
7  * This program is free software: you can redistribute it and/or modify *
8  * it under the terms of the GNU General Public License as published by *
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12  * This program is distributed in the hope that it will be useful, *
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14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
15  * GNU General Public License for more details. *
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17  * You should have received a copy of the GNU General Public License *
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19  * *
20  ***************************************************************************/
21 /**
22  * @file GMath.hpp
23  * @brief Mathematical function definitions
24  * @author Juergen Knoedlseder
25  */
26 
27 #ifndef GMATH_HPP
28 #define GMATH_HPP
29 
30 /* __ Includes ___________________________________________________________ */
31 #include <cmath>
32 
33 /* __ Constants __________________________________________________________ */
34 namespace gammalib {
35  const double pi = 3.141592653589793238462643383279502884197;
36  const double twopi = 6.283185307179586476925286766559005768394;
37  const double fourpi = 12.56637061435917295385057353311801153679;
38  const double pihalf = 1.570796326794896619231321691639751442099;
39  const double inv_pihalf = 0.6366197723675813430755350534900574;
40  const double inv_sqrt4pi = 0.2820947917738781434740397257803862929220;
41  const double inv_sqrt2pi = 0.3989422804014327028632180827116826549172;
42  const double pi2 = pi*pi;
43  const double deg2rad = 0.0174532925199432954743717;
44  const double rad2deg = 57.295779513082322864647722;
45  const double ln2 = 0.6931471805599453094172321214581766;
46  const double ln10 = 2.3025850929940456840179914546843642;
47  const double inv_ln2 = 1.4426950408889634073599246810018921;
48  const double onethird = 1.0/3.0;
49  const double twothird = 2.0/3.0;
50  const double fourthird = 4.0/3.0;
51  const double sqrt_onehalf = std::sqrt(1.0/2.0);
52  const double sqrt_two = std::sqrt(2.0);
53  const double sqrt_pihalf = std::sqrt(pihalf);
54  const double sqrt_twopi = std::sqrt(twopi);
55  const double inv_ln10 = 1.0/ln10;
56  const double inv_loge = 1.0/std::log10(std::exp(1.0));
57 }
58 
59 /* __ Prototypes _________________________________________________________ */
60 namespace gammalib {
61 
62  // Trigonometric functions
63  double acos(const double& arg);
64  double atan2(const double& y, const double& x);
65  double cosd(const double& angle);
66  double sind(const double& angle);
67  double tand(const double& angle);
68  double asind(const double& value);
69  double acosd(const double& value);
70  double atand(const double& value);
71  double atan2d(const double& y, const double& x);
72  void sincosd(const double& angle, double *s, double *c);
73 
74  // Other functions
75  double gammln(const double& arg);
76  double erf(const double& arg);
77  double erfc(const double& arg);
78  double erfinv(const double& arg);
79  double modulo(const double& v1, const double& v2);
80  double plaw_integral(const double& x1,
81  const double& f1,
82  const double& x2,
83  const double& f2);
84  double gauss_integral(const double& x1, const double& x2);
85 }
86 
87 #endif /* GMATH_HPP */
double tand(const double &angle)
Compute tangens of angle in degrees.
Definition: GMath.cpp:192
const double sqrt_twopi
Definition: GMath.hpp:54
const double pi2
Definition: GMath.hpp:42
const double inv_ln2
Definition: GMath.hpp:47
const double inv_loge
Definition: GMath.hpp:56
const double pi
Definition: GMath.hpp:35
double erf(const double &arg)
Computes error function.
Definition: GMath.cpp:417
double gauss_integral(const double &x1, const double &x2)
Returns the integral of a Gaussian function.
Definition: GMath.cpp:605
const double fourthird
Definition: GMath.hpp:50
const double onethird
Definition: GMath.hpp:48
double modulo(const double &v1, const double &v2)
Returns the remainder of the division.
Definition: GMath.cpp:526
const double ln2
Definition: GMath.hpp:45
double acos(const double &arg)
Computes acos by avoiding NaN due to rounding errors.
Definition: GMath.cpp:69
const double sqrt_two
Definition: GMath.hpp:52
const double inv_sqrt4pi
Definition: GMath.hpp:40
const double ln10
Definition: GMath.hpp:46
double atand(const double &value)
Compute arc tangens in degrees.
Definition: GMath.cpp:282
const double pihalf
Definition: GMath.hpp:38
const double deg2rad
Definition: GMath.hpp:43
GVector sqrt(const GVector &vector)
Computes square root of vector elements.
Definition: GVector.cpp:1268
double acosd(const double &value)
Compute arc cosine in degrees.
Definition: GMath.cpp:218
double erfinv(const double &arg)
Computes inverse error function.
Definition: GMath.cpp:463
const double inv_pihalf
Definition: GMath.hpp:39
const double twothird
Definition: GMath.hpp:49
void sincosd(const double &angle, double *s, double *c)
Compute sine and cosine of angle in degrees.
Definition: GMath.cpp:342
double erfc(const double &arg)
Computes complementary error function.
Definition: GMath.cpp:450
const double sqrt_pihalf
Definition: GMath.hpp:53
double plaw_integral(const double &x1, const double &f1, const double &x2, const double &f2)
Returns the integral of a power law.
Definition: GMath.cpp:566
double gammln(const double &arg)
Computes logarithm of gamma function.
Definition: GMath.cpp:383
double atan2d(const double &y, const double &x)
Compute arc tangens in degrees.
Definition: GMath.cpp:308
double cosd(const double &angle)
Compute cosine of angle in degrees.
Definition: GMath.cpp:134
const double inv_sqrt2pi
Definition: GMath.hpp:41
double asind(const double &value)
Compute arc sine in degrees.
Definition: GMath.cpp:250
double atan2(const double &y, const double &x)
Compute arc tangens in radians.
Definition: GMath.cpp:102
GVector exp(const GVector &vector)
Computes exponential of vector elements.
Definition: GVector.cpp:1142
const double fourpi
Definition: GMath.hpp:37
const double twopi
Definition: GMath.hpp:36
const double rad2deg
Definition: GMath.hpp:44
const double sqrt_onehalf
Definition: GMath.hpp:51
const double inv_ln10
Definition: GMath.hpp:55
double sind(const double &angle)
Compute sine of angle in degrees.
Definition: GMath.cpp:163
GVector log10(const GVector &vector)
Computes base10 logarithm of vector elements.
Definition: GVector.cpp:1205