source: issm/trunk-jpl/src/c/shared/Random/randomgenerator.h@ 26587

Last change on this file since 26587 was 26587, checked in by bulthuis, 3 years ago

CHG: add member functions for random generators in a separate file
  • Property svn:executable set to *
File size: 1.4 KB
Line 
1/*!\file: randomgenerator.h
2 * \brief prototypes for randomgenerator.h
3 */
4
5#ifndef _RANDOMGENERATOR_H_
6#define _RANDOMGENERATOR_H_
7
8#undef M_PI
9#define M_PI 3.141592653589793238462643
10
11class rnd_uniform_distribution
12{
13
14 private:
15 int a;
16 int c;
17 unsigned int m;
18 unsigned _seed;
19 double lbound;
20 double ubound;
21
22 int drnd() { return( _seed = ( a * _seed + c ) % m ); }
23
24 public:
25
26 /*constructors, destructors: */
27 rnd_uniform_distribution();
28 rnd_uniform_distribution(double a_1,double a_2);
29 ~rnd_uniform_distribution();
30
31 void seed( unsigned int s ) { _seed = s; }
32 unsigned int get_seed() { return _seed; }
33 double generator() { return (ubound-lbound)*(double) drnd()/ m + lbound; }
34
35};
36
37class rnd_normal_distribution
38{
39
40 private:
41 unsigned _seed;
42 double mean;
43 double sdev;
44
45 public:
46
47 /*constructors, destructors: */
48 rnd_normal_distribution();
49 rnd_normal_distribution(double m,double s);
50 ~rnd_normal_distribution();
51
52 void seed( unsigned int s ) { _seed = s; }
53 double generator()
54 {
55 rnd_uniform_distribution unifdistri;
56 unifdistri.seed(_seed);
57
58 double u1 = unifdistri.generator();
59 double u2 = unifdistri.generator();
60
61 double R = sqrt(-2*log(u1));
62 double theta = 2*M_PI*u2;
63
64 seed(unifdistri.get_seed());
65
66 return mean + sdev * (R*cos(theta));
67
68 }
69
70};
71
72#endif //ifndef _RANDOMGENERATOR_H_
Note: See TracBrowser for help on using the repository browser.