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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).

     allbox;  lbw24  lb  lb  l  l  l.   Interface Attribute Value T{ carg(),
     cargf(), cargl() T}   Thread safety  MT-Safe

CONFORMING TO

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

SEE ALSO

     cabs(3), complex(7)

COLOPHON

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                                2017-09-15                           CARG(3)