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scalb(3)                Library Functions Manual                scalb(3)

ИМЯ

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

БИБЛИОТЕКА

       Math library (libm, -lm)

СИНТАКСИС

       #include <math.h>

       [[deprecated]] double scalb(double x, double exp);
       [[deprecated]] float scalbf(float x, float exp);
       [[deprecated]] long double scalbl(long double x, long double exp);

   Feature Test Macro Requirements for glibc (see
   feature_test_macros(7)):

       scalb():
           _XOPEN_SOURCE >= 500
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

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

ОПИСАНИЕ

       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>.

ЗНАЧЕНИЕ, ВОЗВРАЩАЕМОЕ ФУНКЦИЕЙ

       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.

ОШИБКИ

       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.

АТРИБУТЫ

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌─────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                           │ Attribute     │ Value   │
       ├─────────────────────────────────────┼───────────────┼─────────┤
       │ scalb(), scalbf(), scalbl()         │ Thread safety │ MT-Safe │
       └─────────────────────────────────────┴───────────────┴─────────┘

СТАНДАРТЫ

       None.

ИСТОРИЯ

       scalb()
              4.3BSD.  Obsolescent in POSIX.1-2001; Removed in
              POSIX.1-2008, recommending the use of scalbln(3),
              scalblnf(3), or scalblnl(3) instead.

НЕДОСТАТКИ

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

СМОТРИТЕ ТАКЖЕ

       ldexp(3), scalbln(3)

КОЛОФОН

       This page is part of the man-pages (Linux kernel and C library
       user-space interface documentation) project.  Information about
       the project can be found at 
       ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report
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       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
       This page was obtained from the tarball man-pages-6.9.1.tar.gz
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       2024-06-26.  If you discover any rendering problems in this HTML
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       part of the original manual page), send a mail to
       man-pages@man7.org

Linux man-pages 6.9.1          2024-05-02                       scalb(3)

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