NAME

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

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():
           _XOPEN_SOURCE >= 500
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
       scalbf(), scalbl():
           _XOPEN_SOURCE >= 600
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

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
              errno is set to EDOM.  An invalid floating-point exception (FE_INVALID) is raised.

       Range error, overflow
              errno is set to ERANGE.  An overflow floating-point exception (FE_OVERFLOW) is raised.

       Range error, underflow
              errno is set to ERANGE.  An underflow floating-point exception (FE_UNDERFLOW) is raised.

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

BUGS

       Before glibc 2.20, these functions did not set errno for domain and range errors.

SEE ALSO

       ldexp(3), scalbln(3)

COLOPHON

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       information   about   reporting   bugs,   and   the  latest  version  of  this  page,  can  be  found  at
       https://www.kernel.org/doc/man-pages/.

                                                   2020-06-09                                           SCALB(3)