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, 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(): _XOPEN_SOURCE >= 500 || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
_XOPEN_SOURCE >= 600 || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
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
On success, these functions return
x * FLT_RADIX **
exp is a NaN, a NaN is returned.
x is positive infinity (negative infinity), and
exp is not negative infinity, positive infinity (negative infinity) is returned.
x is +0 (-0), and
exp is not positive infinity, +0 (-0) is returned.
x is zero, and
exp is positive infinity, a domain error occurs, and a NaN is returned.
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
If the result underflows, a range error occurs, and the functions return zero, with a sign the same as
See math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following errors can occur:
xis 0, and
expis positive infinity, or
xis positive infinity and
expis negative infinity and the other argument is not a NaN
An invalid floating-point exception (FE_INVALID) is raised.
An overflow floating-point exception (FE_OVERFLOW) is raised.
An underflow floating-point exception (FE_UNDERFLOW) is raised.
These functions do not set
For an explanation of the terms used in this section, see attributes(7).
|scalb(), scalbf(), scalbl()||Thread safety||MT-Safe|
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.
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