Man Linux: Main Page and Category List

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(), 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 3.24 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