exp(3) — Linux manual page


EXP(3)                    Linux Programmer's Manual                   EXP(3)

NAME         top

       exp, expf, expl - base-e exponential function

SYNOPSIS         top

       #include <math.h>

       double exp(double x);
       float expf(float x);
       long double expl(long double x);

       Link with -lm.

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

       expf(), expl():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION         top

       These functions return the value of e (the base of natural
       logarithms) raised to the power of x.

RETURN VALUE         top

       On success, these functions return the exponential value of x.

       If x is a NaN, a NaN is returned.

       If x is positive infinity, positive infinity is returned.

       If x is negative infinity, +0 is returned.

       If the result underflows, a range error occurs, and zero is returned.

       If the result overflows, a range error occurs, and the functions
       return +HUGE_VAL, +HUGE_VALF, or +HUGE_VALL, respectively.

ERRORS         top

       See math_error(7) for information on how to determine whether an
       error has occurred when calling these functions.

       The following errors can occur:

       Range error, overflow
              errno is set to ERANGE.  An overflow floating-point exception
              (FE_OVERFLOW) is raised.

       Range error, underflow
              errno is set to ERANGE.  An underflow floating-point exception
              (FE_UNDERFLOW) is raised.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see

       │Interface             Attribute     Value   │
       │exp(), expf(), expl() │ Thread safety │ MT-Safe │

CONFORMING TO         top

       C99, POSIX.1-2001, POSIX.1-2008.

       The variant returning double also conforms to SVr4, 4.3BSD, C89.

SEE ALSO         top

       cbrt(3), cexp(3), exp10(3), exp2(3), expm1(3), sqrt(3)

COLOPHON         top

       This page is part of release 5.07 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at

                                 2017-09-15                           EXP(3)

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