Compute the complex inverse hyperbolic tangent
#include <complex.h> double complex catanh( double complex z ); float complex catanhf( float complex z ); long double complex catanhl( long double complex z );
These functions compute the complex inverse hyperbolic tangent of z, with branch cuts outside the interval [−1; +1] along the real axis.
To check for error situations, use feclearexcept() and fetestexcept(). For example:
The complex inverse hyperbolic tangent of z, in the range of a half-strip mathematically unbounded along the real axis and in the interval [−iπ/2; +iπ/2] along the imaginary axis.
| If z is: | These functions return: | Errors: |
|---|---|---|
| 0 + 0i | 0 + 0i | — |
| 0 + NaNi | 0 + NaNi | — |
| 1 + 0i | Inf + 0i | FE_DIVBYZERO |
| x + Infi, for any finite positive x | 0 + (π/2)i | — |
| x + NaNi, for any finite nonzero x | NaN + NaNi | — |
| Inf + yi, for any finite positive y | 0 + (π/2)i | — |
| Inf + Infi | 0 + (π/2)i | — |
| Inf + NaNi | 0 + NaNi | — |
| NaN + yi, for any finite y | NaN + NaNi | — |
| NaN + Infi | ±0 + (π/2)i, where the sign of the real part is unspecified | — |
| NaN + NaNi | NaN + NaNi | — |
These functions raise FE_INEXACT if the FPU reports that the result can't be exactly represented as a floating-point number.
| Safety: | |
|---|---|
| Cancellation point | No |
| Interrupt handler | No |
| Signal handler | No |
| Thread | Yes |