Manual Pages for UNIX Operating System command usage for man expf

Mathematical Library Functions                            exp(3M)



NAME
     exp, expf, expl - exponential function

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

     double exp(double x);


     float expf(float x);


     long double expl(long double x);


DESCRIPTION
     These functions compute the base-e exponential of x.

RETURN VALUES
     Upon  successful  completion,  these  functions  return  the
     exponential value of x.


     If the correct value would cause  overflow,  a  range  error
     occurs  and  exp(),  expf(),  and  expl()  return  HUGE_VAL,
     HUGE_VALF, and HUGE_VALL, respectively.


     If x is NaN, a NaN is returned.


     If x is +_0, 1 is returned.


     If x is +Inf, x is returned.


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

ERRORS
     These functions will fail if:

     Range Error    The result overflows.

                    If the integer expression (math_errhandling &
                    MATH_ERREXCEPT)  is  non-zero,  the  overflow
                    floating-point exception is raised.

                    The exp() function sets errno  to  ERANGE  if



SunOS 5.11          Last change: 12 Jul 2006                    1






Mathematical Library Functions                            exp(3M)



                    the result overflows.


USAGE
     An application wanting to check for exceptions  should  call
     feclearexcept(FE_ALL_EXCEPT) before calling these functions.
     On  return,  if  fetestexcept(FE_INVALID  |  FE_DIVBYZERO  |
     FE_OVERFLOW  |  FE_UNDERFLOW)  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.


     An application can also set errno to 0 before calling exp().
     On  return, if errno is non-zero, an error has occurred. The
     expf() and expl() functions do not set errno.

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



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|
    | MT-Level                    | MT-Safe                     |
    |_____________________________|_____________________________|
    | Standard                    | See standards(5).           |
    |_____________________________|_____________________________|


SEE ALSO
     feclearexcept(3M),  fetestexcept(3M),  isnan(3M),   log(3M),
     math.h(3HEAD),  matherr(3M),  mp(3MP),  attributes(5), stan-
     dards(5)

















SunOS 5.11          Last change: 12 Jul 2006                    2