exp, expf
Visual Studio .NET 2003
Calculates the exponential.
double exp( double x ); float exp( float x ); // C++ only long double exp( long double x ); // C++ only float expf( float x );
Parameter
- x
- Floating-point value.
Return Value
The exp function returns the exponential value of the floating-point parameter, x, if successful. On overflow, the function returns INF (infinite) and on underflow, exp returns 0.
| Input | SHE Exception | Matherr Exception |
|---|---|---|
| ± QNAN,IND | None | _DOMAIN |
| ± ∞ | INVALID | _DOMAIN |
| x ≥ 7.097827e+002 | INEXACT+OVERFLOW | OVERFLOW |
| X ≤ -7.083964e+002 | INEXACT+UNDERFLOW | UNDERFLOW |
exp has an implementation that uses Streaming SIMD Extensions 2 (SSE2). See _set_SSE2_enable for information and restrictions on using the SSE2 implementation.
Remarks
C++ allows overloading, so you can call overloads of exp. In a C program, exp always takes and returns a double.
Requirements
| Function | Required header | Compatibility |
|---|---|---|
| exp, expf | <math.h> | ANSI, Win 98, Win Me, Win NT, Win 2000, Win XP |
For additional compatibility information, see Compatibility in the Introduction.
Libraries
All versions of the C run-time libraries.
Example
// crt_exp.c
#include <math.h>
#include <stdio.h>
int main( void )
{
double x = 2.302585093, y;
y = exp( x );
printf( "exp( %f ) = %f\n", x, y );
}
Output
exp( 2.302585 ) = 10.000000
See Also
Floating-Point Support Routines | log | Run-Time Routines and .NET Framework Equivalents
