CARG(3) 						     Linux Programmer's Manual							   CARG(3)

NAME

       carg, cargf, cargl - calculate the complex argument

SYNOPSIS

       #include <complex.h>

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

       Link with -lm.

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 the range of [-pi,pi].

VERSIONS

       These functions first appeared in glibc in version 2.1.

ATTRIBUTES

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

       +-------------------------+---------------+---------+
       |Interface		 | Attribute	 | Value   |
       +-------------------------+---------------+---------+
       |carg(), cargf(), cargl() | Thread safety | MT-Safe |
       +-------------------------+---------------+---------+
CONFORMING TO

       C99, POSIX.1-2001, POSIX.1-2008.

SEE ALSO

       cabs(3), complex(7)

COLOPHON

       This  page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

								    2017-09-15								   CARG(3)