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scalb, scalbf, scalbl - multiply floating-point number by integral power of radix (OBSOLETE)
#include <math.h> double scalb(double x, double exp); float scalbf(float x, double exp); long double scalbl(long double x, double exp); Link with -lm. Feature Test Macro Requirements for glibc (see feature_test_macros(7)): scalb(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED scalbf(), scalbl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600
These functions multiply their first argument x by FLT_RADIX (probably 2) to the power of exp, that is: x * FLT_RADIX ** exp The definition of FLT_RADIX can be obtained by including <float.h>.
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.
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. These functions do not set errno.
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
This page is part of release 3.35 of the Linux man-pages project. 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)