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);

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 carg(z) = atan(creal(z) / cimag(z)).

The return value is the range of [-pi,pi].

C99

cabs(3), complex(5)