huschi.net

SCALB(3)                   Linux Programmer's Manual                  SCALB(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():
           _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 ||
           _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
       scalbf(), scalbl():
           _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600
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.
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() func-
       tion 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 3.53 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

                                  2013-03-23                          SCALB(3)