carg, cargf, cargl - calculate the complex argument
double carg(double complex
float cargf(float complex
long double cargl(long double complex
These functions calculate the complex argument (also called phase
z, with a branch cut along the negative real
A complex number can be described by two real coordinates. One may use rectangular coordinates and gets
z = x + I * y
x = creal(z) and
y = cimag(z).
Or one may use polar coordinates and gets
z = r * cexp(I * a)
r = cabs(z) is the "radius", the "modulus", the
absolute value of
a = carg(z) is the "phase
angle", the argument of
tan(carg(z)) = cimag(z) / creal(z)
The return value is in the range of [-pi,pi].
These functions first appeared in glibc in version 2.1.
C99, POSIX.1-2001, POSIX.1-2008.
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