scalbl(3)

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
          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

   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

SEE ALSO

   ldexp(3), scalbln(3)

COLOPHON

   This  page  is  part of release 4.09 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)

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