random.h

来自「改算法基于遗传算法」· C头文件 代码 · 共 72 行

#ifndef RAND_H
#define RAND_H

//#include <stdlib.h>
#include <math.h>

#ifndef	M_PI
#define	M_PI ((double)3.14159265358979323)
#endif

#ifndef RAND_MAX 
#define RAND_MAX 2147483647
#endif

#define RAND16_MAX 65535

#ifdef __cplusplus
extern "C" {
#endif

#define STATE_SIZE 97
const double randbit = 1.0 /16777216.0;

class random_number
{
    unsigned int ni;
    unsigned int nj;
    double u[STATE_SIZE];
    double c, cd, cm;
    unsigned int collapse (int anyint, unsigned int size);
    void start_random_number(int seed_a, int seed_b);
    double next_random_number(void);


public:
    random_number(int );
    random_number();
    double    urand(double r = 1.0) {
	return r*next_random_number();
    }
    double nrand(void){
      static int    fl_rand = 0;
      static double    x1;
      static double    x2;
      double r1;
      double r2;
      
      if (!fl_rand) {
        fl_rand = 1;
        r1 = next_random_number() + randbit; /* (0,1] */
        r2 = next_random_number();      /* [0,1) */
        x1 = (double)sqrt(-2 * (double)log(r1));
        x2 = (double)(2 * M_PI * r2);
        return x1 * (double)cos(x2);
      }
      else {
        fl_rand = 0;
        return x1 * (double)sin(x2);
      }
    }
    double cauchy(double scale=1.0){
      return  tan(3.14159265*(next_random_number() - 0.5))*scale;
      //      return  tan(3.14159*(next_random_number()))*scale;
    }

};
#ifdef __cplusplus
}
#endif

#endif