NAME
scalbn() — scale exponent of a radix-independent floating-point number
SYNOPSIS
#include <math.h>
double scalbn(double x, int n);
DESCRIPTION
The
scalbn()
function returns
x * rn,
where
r
is the radix of the machine's floating-point arithmetic. When
r
is 2 (as it is on all PA-RISC systems),
scalbn()
is equivalent to
ldexp().
The
scalb()
function is recommended by the IEEE-754 standard for
floating-point arithmetic. The ISO/ANSI C committee has approved the
scalbn()
function for inclusion in the C9X draft standard.
To use this function, compile either with the default
-Ae
option or with the
-Aa
and
-D_HPUX_SOURCE
options. Make sure your program includes
<math.h>.
Link in the math library by specifying
-lm
on the compiler or linker command line.
RETURN VALUE
Upon successful completion, the
scalbn()
function returns
x * rn.
scalbn(-x, n)
and
-scalbn(x, n)
are equivalent.
If
x
is ±INFINITY,
zero, or a NaN,
scalbn()
returns
x.
If the correct value after rounding would be smaller in magnitude than
MINDOUBLE,
scalbn()
returns zero.
If the correct value would overflow,
scalbn()
returns
±INFINITY
(according to the sign of
x).
ERRORS
No errors are defined.
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