frexp(3C) frexp(3C)
NAME
frexp, ldexp, modf - manipulate parts of floating-point
numbers
SYNOPSIS
double frexp (value, eptr)
double value;
int *eptr;
double ldexp (value, exp)
double value;
int exp ;
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 ERRANGE.
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