exp
Section: C Library Functions (3)
Updated: 2023-02-05
Index
Return to Main Contents
NAME
exp, expf, expl - base-e exponential function
LIBRARY
Math library
(libm, -lm)
SYNOPSIS
#include <math.h>
double exp(double x);
float expf(float x);
long double expl(long double x);
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 <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
DESCRIPTION
These functions return the value of e (the base of natural
logarithms) raised to the power of
x.
RETURN VALUE
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
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
For an explanation of the terms used in this section, see
attributes(7).
| Interface | Attribute | Value
|
|
exp(),
expf(),
expl()
| Thread safety | MT-Safe
|
STANDARDS
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning
double
also conforms to
SVr4, 4.3BSD.
SEE ALSO
cbrt(3),
cexp(3),
exp10(3),
exp2(3),
expm1(3),
sqrt(3)
Index
- NAME
-
- LIBRARY
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- ATTRIBUTES
-
- STANDARDS
-
- SEE ALSO
-
This document was created by
man2html,
using the manual pages.
Time: 20:08:40 GMT, April 18, 2024