NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | CONFORMING TO | SEE ALSO | COLOPHON

SCALB(3)                  Linux Programmer's Manual                 SCALB(3)

NAME         top

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

SYNOPSIS         top

       #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         top

       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         top

       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         top

       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         top

       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         top

       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

SEE ALSO         top

       ldexp(3), scalbln(3)

COLOPHON         top

       This page is part of release 4.08 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.

                                 2016-03-15                         SCALB(3)