Implementation status: to be implemented
double complex catan(double complex z);
float complex catanf(float complex z);
long double complex catanl(long double complex z);
The functions compute the complex arc tangent of z, with branch cuts outside the interval
[-i, +i] along the imaginary axis.
z - a complex number.
These functions return the complex arc tangent value, in the range of a strip mathematically unbounded along the imaginary axis and in the interval [-π/2, +π/2] along the real axis.
No errors are defined.