table of contents
EXP(3) | Linux Programmer's Manual | EXP(3) |
NAME¶
exp, expf, expl - base-e exponential function
SYNOPSIS¶
#include <math.h>
double exp(double x); float expf(float x); long double expl(long double x);
Link with -lm.
expf(), expl():
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 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 |
CONFORMING TO¶
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning double also conforms to SVr4, 4.3BSD, C89.
SEE ALSO¶
COLOPHON¶
This page is part of release 5.10 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 https://www.kernel.org/doc/man-pages/.
2017-09-15 |