💾 Archived View for gmi.noulin.net › man › man3 › scalbn.3.gmi captured on 2023-09-08 at 17:06:45. Gemini links have been rewritten to link to archived content

View Raw

More Information

-=-=-=-=-=-=-

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

NAME
       scalbn, scalbnf, scalbnl, scalbln, scalblnf, scalblnl - multiply floating-point number by integral power of radix

SYNOPSIS
       #include <math.h>

       double scalbln(double x, long exp);
       float scalblnf(float x, long exp);
       long double scalblnl(long double x, long exp);

       double scalbn(double x, int exp);
       float scalbnf(float x, int exp);
       long double scalbnl(long double x, int exp);

       Link with -lm.

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

       scalbln(), scalblnf(), scalblnl():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE

       scalbn(), scalbnf(), scalbnl():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* Glibc <= 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 is a NaN, a NaN is returned.

       If x is positive infinity (negative infinity), positive infinity (negative infinity) is returned.

       If x is +0 (-0), +0 (-0) 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:

       Range error, overflow
              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.

VERSIONS
       These functions first appeared in glibc in version 2.1.

ATTRIBUTES
       For an explanation of the terms used in this section, see attributes(7).

       ┌──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │Interface                                                                                                                             │ Attribute     │ Value   │
       ├──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │scalbn(), scalbnf(), scalbnl(), scalbln(), scalblnf(), scalblnl()                                                                     │ Thread safety │ MT-Safe │
       └──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

CONFORMING TO
       C99, POSIX.1-2001, POSIX.1-2008.

NOTES
       These  functions differ from the obsolete functions described in scalb(3) in the type of their second argument.  The functions described on this page have a sec‐
       ond argument of an integral type, while those in scalb(3) have a second argument of type double.

       If FLT_RADIX equals 2 (which is usual), then scalbn() is equivalent to ldexp(3).

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

SEE ALSO
       ldexp(3), scalb(3)

                                                                               2021-03-22                                                                     SCALBLN(3)