NAME
frexp() — extract mantissa and exponent from double-precision number
SYNOPSIS
#include <math.h>
double frexp(double num, int *exp);
DESCRIPTION
The
frexp()
function breaks a floating-point number into a normalized fraction and
an integral power of 2. It stores the integer exponent in the
int
object pointed to by
exp.
To use this function, make sure your program includes
<math.h>,
and link in the math library by specifying
-lm
on the compiler or linker command line.
RETURN VALUE
The
frexp()
function returns the value
x,
such that
x
is a
double
with magnitude in the interval [0.5, 1] or zero, and
num
equals
x
times 2 raised to the power
*exp.
If
num
is zero, both parts of the result are zero.
If
num
is NaN,
frexp()
returns NaN, and the value of
*exp
is unspecified.
If
num
is ±INFINITY,
frexp()
returns
num,
and the value of
*exp
is unspecified.
ERRORS
No errors are defined.
STANDARDS CONFORMANCE
frexp(): SVID3, XPG4.2, ANSI C
Printable version
