SIMPLE SOLUTIONS

SCALB(3) - man page online | library functions

Multiply floating-point number by integral power of radix (OBSOLETE).

Chapter
2015-03-02
SCALB(3)                            Linux Programmer's Manual                            SCALB(3)

NAME scalb, scalbf, scalbl - multiply floating-point number by integral power of radix (OBSO‐ LETE)
SYNOPSIS #include <math.h> double scalb(double x, double exp); float scalbf(float x, float exp); long double scalbl(long double x, long 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
DESCRIPTION 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>.
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. These functions do not set errno.
ATTRIBUTES For an explanation of the terms used in this section, see attributes(7). ┌─────────────────────────────┬───────────────┬─────────┐ │Interface │ Attribute │ Value │ ├─────────────────────────────┼───────────────┼─────────┤ │scalb(), scalbf(), scalbl() │ Thread safety │ MT-Safe │ └─────────────────────────────┴───────────────┴─────────┘
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