cexp(), cexpf(), cexpl()

Compute the complex base-e exponential of a complex number

Synopsis:

```#include <complex.h>

double complex cexp(double complex z );

float complex cexpf(float complex z );

long double complex cexpl(long double complex z );
```

Arguments:

z
The complex value that you want to compute the complex base-e exponential of.

Library:

libm

Use the -l m option to qcc to link against this library.

Description:

These functions compute the complex base-e exponential of z. If z = x+iy, the complex exponential is:

```ez = ex cis(y)
= ex (cos(y) + i sin(y))
```

The exponential function is an entire function in the complex plane and has no branch cuts.

To check for error situations, use feclearexcept() and fetestexcept(). For example:

• Call feclearexcept(FE_ALL_EXCEPT) before calling cexp(), cexpf(), or cexpl().
• On return, if fetestexcept(FE_ALL_EXCEPT) is nonzero, then an error has occurred.

Returns:

If no errors occur, the complex base-e exponential of z.

If z is: These functions return: Errors:
±0 + 0i 1 + 0i
x + Infi, for any finite x NaN + NaNi FE_INVALID
x + NaNi, for any finite x NaN + NaNi
Inf + 0i Inf + 0i
-Inf + yi, for any finite y 0 * cis(y)
Inf + yi, for any finite nonzero y Inf * cis(y)
-Inf + Infi ±0 ± 0i, where the signs are unspecified
Inf + Infi ±Inf + NaNi, where the sign of the real part is unspecified FE_INVALID
-Inf + NaNi ±0 ± 0i, where the signs are unspecified
Inf + NaNi ±Inf - NaNi, where the sign of the real part is unspecified
NaN + 0i NaN + 0i
NaN + yi, for any nonzero y NaN + NaNi
NaN + NaNi NaN + NaNi

where cis(y) is cos(y) + i sin(y).

These functions raise FE_INEXACT if the FPU reports that the result can't be exactly represented as a floating-point number.

Classification:

Safety:
Cancellation point No
Interrupt handler No
Signal handler No