ldexp(3) [redhat man page]

LDEXP(3)						     Linux Programmer's Manual							  LDEXP(3)

NAME

       ldexp - multiply floating-point number by integral power of 2

SYNOPSIS

       #include <math.h>

       double ldexp(double x, int exp);

DESCRIPTION

       The ldexp() function returns the result of multiplying the floating-point number x by 2 raised to the power exp.

CONFORMING TO

       SVID 3, POSIX, BSD 4.3, ISO 9899

SEE ALSO

       frexp(3), modf(3)

BSD
								    1993-06-06								  LDEXP(3)

LDEXP(3)						     Linux Programmer's Manual							  LDEXP(3)

NAME

       ldexp, ldexpf, ldexpl - multiply floating-point number by integral power of 2

SYNOPSIS

       #include <math.h>

       double ldexp(double x, int exp);
       float ldexpf(float x, int exp);
       long double ldexpl(long double x, int exp);

       Link with -lm.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       ldexpf(), ldexpl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99

DESCRIPTION

       The ldexp() function returns the result of multiplying the floating-point number x by 2 raised to the power exp.

RETURN VALUE

       On success, these functions return x * (2^exp).

       If exp is zero, then x is returned.

       If x is a NaN, a NaN is returned.

       If x is positive infinity (negative infinity), positive infinity (negative infinity) is returned.

       If the result underflows, an  range error occurs, and zero is returned.

       If  the	result	overflows, a range error occurs, and the functions return HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively, with a sign the
       same as x.

ERRORS

       See math_error(7) for information on how to determine whether an error has occurred when calling these functions.

       The following errors can occur:

       Range error, overflow
	      errno is set to ERANGE.  An overflow floating-point exception (FE_OVERFLOW) is raised.

       Range error, underflow
	      errno is set to ERANGE.  An underflow floating-point exception (FE_UNDERFLOW) is raised.

CONFORMING TO

       C99, POSIX.1-2001.  The variant returning double also conforms to SVr4, 4.3BSD, C89.

SEE ALSO

       frexp(3), modf(3), scalbln(3)

COLOPHON

       This page is part of release 3.25 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

								    2008-08-05								  LDEXP(3)