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
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
|
/********************************************************************************
* *
* R a n d o m N u m b e r G e n e r a t o r *
* *
*********************************************************************************
* Copyright (C) 2007,2022 by Jeroen van der Zijp. All Rights Reserved. *
*********************************************************************************
* This library is free software; you can redistribute it and/or modify *
* it under the terms of the GNU Lesser General Public License as published by *
* the Free Software Foundation; either version 3 of the License, or *
* (at your option) any later version. *
* *
* This library is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/> *
********************************************************************************/
#include "xincs.h"
#include "fxver.h"
#include "fxdefs.h"
#include "fxmath.h"
#include "FXRandom.h"
/*
Notes:
- Algorithm based on Numerical Recipes, 3ed, pp. 351-352.
- Original algorithm George Marsaglia, "Random number generators",
Journal of Modern Applied Statistical Methods 2, No. 2, 2003.
- Different shift-counts are certainly possible, and produce different
sequences (of the same period), see G. Marsaglia, "Xorshift RNGs".
- New shift counts based on the paper "An experimental exploration of
Marsaglia's xorshift generators, scrambled", Sebastiano Vigna, 2014.
*/
#define SHIFTA 12
#define SHIFTB 25
#define SHIFTC 27
using namespace FX;
namespace FX {
/*******************************************************************************/
// Construct random generator with default seed
FXRandom::FXRandom():state(FXULONG(4101842887655102017)){
}
// Construct random generator with given seed s
FXRandom::FXRandom(FXulong s):state(FXULONG(4101842887655102017)^s){
}
// Initialize seed
void FXRandom::seed(FXulong s){
state=s^FXULONG(4101842887655102017);
}
// Generate next state
FXulong FXRandom::next(){
state^=state>>SHIFTA;
state^=state<<SHIFTB;
state^=state>>SHIFTC;
return state;
}
// Get random long
FXulong FXRandom::randLong(){
return next()*FXULONG(2685821657736338717);
}
// Get random double
FXfloat FXRandom::randFloat(){
FXlong num=(FXlong)randLong();
return Math::fabs(num*1.0842021724855044340074528008699e-19f);
}
// Get random double
FXdouble FXRandom::randDouble(){
FXlong num=(FXlong)randLong();
return Math::fabs(num*1.0842021724855044340074528008699e-19);
}
}
|
