expm1, expm1f, expm1l
The latest version of this topic can be found at expm1, expm1f, expm1l.
Computes the base-e exponential of a value, minus one.
Syntax
double expm1(
double x
);
float expm1(
float x
); // C++ only
long double expm1(
long double x
); // C++ only
float expm1f(
float x
);
long double expm1l(
long double x
);
Parameters
x
The floating-point exponential value.
Return Value
The expm1 functions return a floating-point value that represents ex – 1, if successful. On overflow, expm1 returns HUGE_VAL, expm1f returns HUGE_VALF, expm1l returns HUGE_VALL, and errno is set to ERANGE. For more information about return codes, see errno, _doserrno, _sys_errlist, and _sys_nerr.
Remarks
Because C++ allows overloading, you can call overloads of expm1 that take and return float and long double values. In a C program, expm1 always takes and returns a double.
Requirements
| Routine | Required header |
|---|---|
expm1, expm1f, expm1l |
<math.h> |
For additional compatibility information, see Compatibility.
.NET Framework Equivalent
Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.