6.2.24 catan Function

Calculates the complex arc tangent function of a double precision complex value.

Include

<complex.h>

Prototype

double complex catan(double complex z);

Argument

z

value for which to return the complex arc tangent

Return Value

Returns the complex arc tangent of z with no bound along the imaginary axis, in the interval $\mathrm{[-\pi /2,\; +\pi /2]}$ along the real axis, and with branch cuts outside the interval $\mathrm{[-i,\; +i]}$ along the imaginary axis.

Example

See the notes at the beginning of this chapter or section for information on using printf() or scanf() (and other functions reading and writing the stdin or stdout streams) in the example code.

#include <stdio.h>
#include <complex.h>

int main(void)
{
  double complex x, y;

  x = -2.0 + 0.0*I;
  y = catan(x);
  printf("The complex arctan of %f + %fi is %f + %fi\n", creal(x), cimag(x), creal(y), cimag(y));
}

Example Output

The complex arctan of -2.000000 + 0.000000i is -1.107149 + 0.000000i