ldexp -- Floating-Point Conversion: Load Exponent


SYNOPSIS
#include <math.h>
double ldexp (double y, int n);
DESCRIPTION
ldexp
calculates y(2**n).
RETURN VALUE
ldexp
returns the value of type double
that results from the
calculation.
DIAGNOSTICS
If the return value cannot be represented, a warning message is sent to the
standard error file (stderr
). +- HUGE_VAL
is returned if
an overflow occurs; 0 is returned if an underflow occurs.
USAGE NOTES
When used with frexp
, the ldexp
function is useful in situations that require
repeated multiplication by 2. If the next multiplication causes an overflow
or underflow, use frexp
to separate the mantissa from the
exponent. This gives you complete control over the exponent and the mantissa, so you
can operate on them separately without any loss of precision. When you are
finished, use ldexp
to combine the mantissa and exponent again.
RELATED FUNCTIONS
frexp
, _ldexp
SEE ALSO
Mathematical Functions