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, double exp);
       long double scalbl(long double x, double exp);

       Link with -lm.

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

       scalb(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500
       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(),  recom-
       mending 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 3.25 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/.



                                                           2009-03-15                                                   SCALB(3)