carg(3)                    Library Functions Manual                    carg(3)

NAME
       carg, cargf, cargl - calculate the complex argument

LIBRARY
       Math library (libm, -lm)

SYNOPSIS
       #include <complex.h>

       double carg(double complex z);
       float cargf(float complex z);
       long double cargl(long double complex z);

DESCRIPTION
       These functions calculate the complex argument (also called phase
       angle) of z, with a branch cut along the negative real axis.

       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)

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

ATTRIBUTES
       For an explanation of the terms used in this section, see
       attributes(7).

       +--------------------------------------------+---------------+---------+
       |Interface                                   | Attribute     | Value   |
       +--------------------------------------------+---------------+---------+
       |carg (), cargf (), cargl ()                 | Thread safety | MT-Safe |
       +--------------------------------------------+---------------+---------+
STANDARDS
       C11, POSIX.1-2008.

HISTORY
       glibc 2.1.  C99, POSIX.1-2001.

SEE ALSO
       cabs(3), complex(7)

Linux man-pages 6.7               2023-10-31                           carg(3)