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**NAME**

scalb, scalbf, scalbl - multiply floating-point number by integral power of radix (OBSOLETE)

**SYNOPSIS**

#include<math.h>doublescalb(doublex,doubleexp);floatscalbf(floatx,doubleexp);longdoublescalbl(longdoublex,doubleexp);Link with-lm. Feature Test Macro Requirements for glibc (seefeature_test_macros(7)):scalb(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDEDscalbf(),scalbl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600

**DESCRIPTION**

These functions multiply their first argumentxbyFLT_RADIX(probably 2) to the power ofexp, that is: x * FLT_RADIX ** exp The definition ofFLT_RADIXcan be obtained by including<float.h>.

**RETURN** **VALUE**

On success, these functions returnx*FLT_RADIX**exp. Ifxorexpis a NaN, a NaN is returned. Ifxis positive infinity (negative infinity), andexpis not negative infinity, positive infinity (negative infinity) is returned. Ifxis +0 (-0), andexpis not positive infinity, +0 (-0) is returned. Ifxis zero, andexpis positive infinity, a domain error occurs, and a NaN is returned. Ifxis an infinity, andexpis negative infinity, a domain error occurs, and a NaN is returned. If the result overflows, a range error occurs, and the functions returnHUGE_VAL,HUGE_VALF, orHUGE_VALL, respectively, with a sign the same asx. If the result underflows, a range error occurs, and the functions return zero, with a sign the same asx.

**ERRORS**

Seemath_error(7) for information on how to determine whether an error has occurred when calling these functions. The following errors can occur: Domain error:xis 0, andexpis positive infinity, orxis positive infinity andexpis 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. These functions do not seterrno.

**CONFORMING** **TO**

scalb() is specified in POSIX.1-2001, but marked obsolescent. POSIX.1-2008 removes the specification ofscalb(), recommending the use ofscalbln(3),scalblnf(3), orscalblnl(3) instead. Thescalb() function is from 4.3BSD.scalbf() andscalbl() are unstandardized;scalbf() is nevertheless present on several other systems

**SEE** **ALSO**

ldexp(3),scalbln(3)

**COLOPHON**

This page is part of release 3.35 of the Linuxman-pagesproject. A description of the project, and information about reporting bugs, can be found at http://man7.org/linux/man- pages/. 2010-09-20 SCALB(3)