|SCALB(3)||Linux Programmer's Manual||SCALB(3)|
NAME¶scalb, scalbf, scalbl - multiply floating-point number by integral power of radix (OBSOLETE)
SYNOPSIS¶#include <math.h> double scalb(double x, double exp);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600
DESCRIPTION¶These functions multiply their first argument x by FLT_RADIX (probably 2) to the power of exp, that is:
x * FLT_RADIX ** expThe definition of FLT_RADIX can be obtained by including <float.h>.
RETURN VALUE¶On success, these functions return x * FLT_RADIX ** exp. If x or exp is a NaN, a NaN is returned. If x is positive infinity (negative infinity), and exp is not negative infinity, positive infinity (negative infinity) is returned. If x is +0 (-0), and exp is not positive infinity, +0 (-0) is returned. If x is zero, and exp is positive infinity, a domain error occurs, and a NaN is returned. If x is an infinity, and exp is negative infinity, a domain error occurs, and a NaN 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. If the result underflows, a range error occurs, and the functions return zero, 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:
- Domain error: x is 0, and exp is positive infinity, or x is positive infinity and exp is negative infinity and the other argument is not a NaN
- An invalid floating-point exception (FE_INVALID) is raised.
- Range error, overflow
- An overflow floating-point exception (FE_OVERFLOW) is raised.
- Range error, underflow
- An underflow floating-point exception (FE_UNDERFLOW) is raised.
CONFORMING TO¶scalb() is specified in POSIX.1-2001, but marked obsolescent. POSIX.1-2008 removes the specification of scalb(), recommending the use of scalbln(3), scalblnf(3), or scalblnl(3) instead. The scalb() function is from 4.3BSD. scalbf() and scalbl() are unstandardized; scalbf() is nevertheless present on several other systems
SEE ALSO¶ldexp(3), scalbln(3)
COLOPHON¶This page is part of release 3.74 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at http://www.kernel.org/doc/man-pages/.