/* Scilab2C FOSSEE IIT Bombay */ #include "rand.h" #include double u8rands(void) { int m=1; const int itwo=2; static int m2=0,halfm=0,ia=0,ic=0,mic=0,iy=0; static double s=0.0; if(m2==0) { /*if first entry,compute machine integer word length*/ while(m>m2) { m2=m; m=itwo*m2; } halfm = m2; /* compute multiplier and increment for linear congruential methos */ ia = 8*(int)(halfm*atan(1.0)/8.0) + 5; ic = 2*(int)(halfm*(0.5-sqrt(3.0)/6.0)) +1; mic = (m2 - ic) + m2; /* s is the scale factor for converting to floating point*/ s = 0.5/halfm; } /* compute next random number */ iy = iy*ia; /* the following statement is for computers which do not allow interger overflow on addition*/ if(iy > mic) { iy = (iy - m2) - m2; } iy = iy + ic; /* the following statement is for computers where the word length for addition is greater than for multiplication */ if(iy/2 > m2) { iy = (iy - m2) - m2; } /* the following statement is for computers where integer overflow affects the sign bit */ if(iy < 0) { iy = (iy + m2) + m2; } return (double)iy*s; }