clcg2.c File Reference

#include "machine.h"
#include <math.h>
#include "sciprint.h"

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Functions
unsigned long	clcg2 ()
int	set_state_clcg2 (double g1, double g2)
void	get_state_clcg2 (double g[])
Variables
static long	s1 = 1234567890
static long	s2 = 123456789

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Function Documentation

unsigned long clcg2

(

)

Definition at line 38 of file clcg2.c.

References s1, s2, and z.

{
  register long k,z;

  /*  s1 = a1*s1 mod m1  (Schrage 's method)  */
  k= s1 /53668;
  s1 =40014*(s1%53668)-k*12211;
  if (s1 < 0) s1 += 2147483563;

  /*  s2 = a2*s2 mod m2  (Schrage 's method)  */
  k=s2/52774;
  s2=40692*(s2%52774)-k*3791;
  if (s2 < 0) s2 += 2147483399;

  /* final step : z = s1-s2 mod m1-1  */
  z = s1 - s2;  /* here z is in [2-m2,m1-2] */
  if (z < 0) z += 2147483562;

  /* NOTE : in the  original implementation the final test is :
   *     if (z < 1) z += 2147483562;
   * 
   *   which is not exactly  z = s1-s2 mod (m1 - 1)
   *
   *   This is also why it is different from the version used by
   *   randlib.
   */
  
  return( (unsigned long) z );
}

void get_state_clcg2

(

double

g[]

)

Definition at line 87 of file clcg2.c.

References s1, and s2.

Referenced by RandI().

{
  g[0] = (double) s1;
  g[1] = (double) s2;
}

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int set_state_clcg2	(	double	g1,
		double	g2
	)

Definition at line 68 of file clcg2.c.

References long, s1, s2, and sciprint().

Referenced by RandI().

{
  
  if ( g1 == floor(g1) && g2 == floor(g2)  && 
       1 <= g1 && g1 <= 2147483562    &&
       1 <= g2 && g2 <= 2147483398 )
    {
      s1 = (long) g1;
      s2 = (long) g2;
      return ( 1 );
    }
  else
    {
      sciprint("\n\r bad seeds for clcg2, must be integers with  s1 in [1, 2147483562]");
      sciprint("\n\r                                        and  s2 in [1, 2147483398]\n\r");
      return ( 0 );
    }
}

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Variable Documentation

long s1 = 1234567890 [static]

Definition at line 35 of file clcg2.c.

Referenced by adjust_pointer_in_string(), bounce4(), bounce_ball(), clcg2(), compgoto_out(), flush_comments(), foldminmax(), get_state_clcg2(), ioseta(), omit_non_f(), putlineno(), rd_Z(), realloc(), samefpconst(), scale_copy(), set_state_clcg2(), struct_eq(), tostring(), and XmuScanlineEqu().

long s2 = 123456789 [static]

Definition at line 36 of file clcg2.c.

Referenced by bounce4(), bounce_ball(), clcg2(), compgoto_out(), get_state_clcg2(), samefpconst(), scale_copy(), set_state_clcg2(), struct_eq(), and XmuScanlineEqu().

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