экспоненциальная функция с основанием e (base-e exponential function)
Имя (Name)
exp, expf, expl - base-e exponential function
Синопсис (Synopsis)
#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 <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
Описание (Description)
These functions return the value of e (the base of natural
logarithms) raised to the power of x.
Возвращаемое значение (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.
Ошибки (Error)
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.
Атрибуты (Attributes)
For an explanation of the terms used in this section, see
attributes(7).
┌──────────────────────────────────────┬───────────────┬─────────┐
│Interface
│ Attribute
│ Value
│
├──────────────────────────────────────┼───────────────┼─────────┤
│exp
(), expf
(), expl
() │ Thread safety │ MT-Safe │
└──────────────────────────────────────┴───────────────┴─────────┘
Стандарты (Conforming to)
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning double also conforms to SVr4, 4.3BSD, C89.
Смотри также (See also)
cbrt(3), cexp(3), exp10(3), exp2(3), expm1(3), sqrt(3)