Mathematical Library Functions                          scalb(3M)



NAME
     scalb, scalbf, scalbl - load exponent of a radix-independent
     floating-point number

SYNOPSIS
     c99 [ flag... ] file... -lm [ library... ]
     #include 

     double scalb(double x, double n);


     float scalbf(float x, float n);


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


DESCRIPTION
     These functions compute x * r^n, where r is the radix of the
     machine's floating point arithmetic. When r is 2, scalb() is
     equivalent to ldexp(3M). The value of r is  FLTRADIX  which
     is defined in .

RETURN VALUES
     Upon successful completion, the scalb() function returns x *
     r^n.


     If x or n is NaN, a NaN is returned.


     If n is 0, x is returned.


     If x is ]Inf and n is not -Inf, x is returned.


     If x is ]0 and n is not ]Inf, x is returned.


     If x is ]0 and n is ]Inf, a domain error occurs and a NaN is
     returned.


     If x is ]Inf and n is -Inf, a domain error occurs and a  NaN
     is returned.


     If the result would cause an overflow, a range error  occurs
     and ]HUGEVAL (according to the sign of x) is returned.





SunOS 5.11          Last change: 12 Jul 2006                    1






Mathematical Library Functions                          scalb(3M)



     For exceptional cases, matherr(3M) tabulates the  values  to
     be  returned  by scalb() as specified by SVID3 and XPG3. See
     standards(5).

ERORS
     These functions will fail if:

     Domain Error    If x is 0 and n is ]Inf, or x is Inf  and  n
                     is -Inf.

                     If the integer expression  (matherrhandling
                     &  MATHEREXCEPT)  is  non-zero,  then  the
                     invalid floating-point exception is raised.


     Range Error     The result would overflow.

                     If the integer expression  (matherrhandling
                     &  MATHEREXCEPT)  is  non-zero,  then  the
                     overflow floating-point exception is raised.


USAGE
     An application wanting to check for exceptions  should  call
     feclearexcept(FEALEXCEPT) before calling these functions.
     On  return,  if  fetestexcept(FEINVALID    FEDIVBYZERO  
     FEOVERFLOW    FEUNDERFLOW)  is non-zero, an exception has
     been raised. An application should either examine the return
     value  or check the floating point exception flags to detect
     exceptions.

ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          See below.                  
    
     MT-Level                     MT-Safe                     
    



     The scalb() function is Standard. The scalbf() and  scalbl()
     functions are Stable.

SEE ALSO




SunOS 5.11          Last change: 12 Jul 2006                    2






Mathematical Library Functions                          scalb(3M)



     feclearexcept(3M), fetestexcept(3M),  ilogb(3M),  ldexp(3M),
     logb(3M),  math.h(3HEAD),  matherr(3M),  scalbln(3M), attri-
     butes(5), standards(5)




















































SunOS 5.11          Last change: 12 Jul 2006                    3