6.2.26 catanl Function

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

Include

<complex.h>

Prototype

long double complex catanl(long 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)
{
  long double complex x, y;

  x = -2.0 + 0.0*I;
  y = catanl(x);
  printf("The complex arctan of %Lf + %Lfi is %Lf + %Lfi\n", creall(x), cimagl(x), creall(y), cimagl(y));
}

Example Output

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