carg, cargf, cargl — calculate the argument
#include <complex.h>
double carg( | 
            double complex | z); | 
          
float
            cargf( | 
            float complex | z); | 
          
long
            double cargl( | 
            long double complex | z); | 
          
![]()  | 
            Note | 
|---|---|
| 
               Link with   | 
          
A complex number can be described by two real coordinates. One may use rectangular coordinates and gets
    z = x + I * y
      where x = creal(z) and y = cimag(z).
Or one may use polar coordinates and gets
    z = r * cexp(I * a)
      where r = cabs(z)
      is the "radius", the "modulus", the absolute value of
      z, and a = carg(z) is the "phase angle",
      the argument of z.
One has:
    tan(carg(z)) = cimag(z) / creal(z)