26 lines
588 B
C
26 lines
588 B
C
|
|
float ran4(long *idum)
|
|
{
|
|
void psdes(unsigned long *lword, unsigned long *irword);
|
|
unsigned long irword,itemp,lword;
|
|
static long idums = 0;
|
|
#if defined(vax) || defined(_vax_) || defined(__vax__) || defined(VAX)
|
|
static unsigned long jflone = 0x00004080;
|
|
static unsigned long jflmsk = 0xffff007f;
|
|
#else
|
|
static unsigned long jflone = 0x3f800000;
|
|
static unsigned long jflmsk = 0x007fffff;
|
|
#endif
|
|
|
|
if (*idum < 0) {
|
|
idums = -(*idum);
|
|
*idum=1;
|
|
}
|
|
irword=(*idum);
|
|
lword=idums;
|
|
psdes(&lword,&irword);
|
|
itemp=jflone | (jflmsk & irword);
|
|
++(*idum);
|
|
return (*(float *)&itemp)-1.0;
|
|
}
|