frexp(3C) — sys5 — Apollo Domain/IX SR9.5



FREXP(3C)                DOMAIN/IX SYS5                 FREXP(3C)



NAME
     frexp, ldexp, modf - split into mantissa and exponent

USAGE
     double frexp (value, eptr)
     double value;
     int *eptr;

     double ldexp (value, exp)
     double value;

     double modf (value, iptr)
     double value, *iptr;


DESCRIPTION
     Every non-zero number can be written uniquely as x*2n where
     the "mantissa" (fraction) x is in the range 0.5 < |x| < 1.0,
     and the "exponent" n is an integer.  Frexp returns the
     mantissa of a double value, and stores the exponent
     indirectly in the location pointed to by eptr.  If value is
     zero, both results returned by frexp are zero.

     Ldexp returns the quantity value*2exp.

     Modf returns the signed fractional part of value and stores
     the integral part indirectly in the location pointed to by
     iptr.

DIAGNOSTICS
     If ldexp would cause overflow, +HUGE is returned (according
     to the sign of value), and errno is set to ERANGE.

     If ldexp would cause underflow, zero is returned and errno
     is set to ERANGE.


















Printed 12/4/86                                           FREXP-1
Museum
