1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
|
#ifndef SALMON_MATH_HPP
#define SALMON_MATH_HPP
// If we have built-ins, do as Boost does
#ifndef BOOST_LIKELY
#if defined(__has_builtin)
#if __has_builtin(__builtin_expect)
#define BOOST_LIKELY(x) __builtin_expect(x, 1)
#endif
#endif
#endif
#ifndef BOOST_UNLIKELY
#if defined(__has_builtin)
#if __has_builtin(__builtin_expect)
#define BOOST_UNLIKELY(x) __builtin_expect(x, 0)
#endif
#endif
#endif
// If we didn't have those built-ins fall back to this
#ifndef BOOST_LIKELY
#define BOOST_LIKELY(x) (x)
#endif
#ifndef BOOST_UNLIKELY
#define BOOST_UNLIKELY(x) (x)
#endif
#include <cmath>
#include <cassert>
namespace salmon {
namespace math {
constexpr double LOG_0 = HUGE_VAL;
constexpr double LOG_1 = 0;
constexpr double LOG_ONEHALF = -0.69314718055994530941;
constexpr double LOG_ORPHAN_PROB = -2.30258509299404568401;
constexpr double EPSILON = 0.375e-10;
const double LOG_EPSILON = log(EPSILON);
inline double log(double v) { return (v > 0) ? std::log(v) : LOG_0; }
inline double exp(double v) { return std::exp(v); }
inline bool isLog0(double v) { return v == LOG_0; }
// Taken from https://github.com/adarob/eXpress/blob/master/src/main.h
inline bool approxEqual(double a, double b, double eps=EPSILON) {
return std::abs(a-b) <= eps;
}
// Taken from https://github.com/adarob/eXpress/blob/master/src/main.h
inline double logAdd(double x, double y) {
if (std::abs(x) == LOG_0) { return y; }
if (std::abs(y) == LOG_0) { return x; }
if (y > x) { std::swap(x,y); }
double sum = x + std::log(1 + std::exp(y-x));
return sum;
}
// Taken from https://github.com/adarob/eXpress/blob/master/src/main.h
inline double logSub(double x, double y) {
if (std::abs(y) == LOG_0) { return x; }
if (x <= y) {
assert(std::fabs(x-y) < 1e-5);
return LOG_0;
}
double diff = x + std::log(1-std::exp(y-x));
return diff;
}
}
}
#endif //SALMON_MATH_HPP
|
