carg(3) — Linux manual page

carg(3)                 Library Functions Manual                 carg(3)

NAME         top

       carg, cargf, cargl - calculate the complex argument

LIBRARY         top

       Math library (libm, -lm)

SYNOPSIS         top

       #include <complex.h>

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

DESCRIPTION         top

       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         top

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

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌─────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                           │ Attribute     │ Value   │
       ├─────────────────────────────────────┼───────────────┼─────────┤
       │ carg(), cargf(), cargl()            │ Thread safety │ MT-Safe │
       └─────────────────────────────────────┴───────────────┴─────────┘

STANDARDS         top

       C11, POSIX.1-2008.

HISTORY         top

       glibc 2.1.  C99, POSIX.1-2001.

SEE ALSO         top

       cabs(3), complex(7)

COLOPHON         top

       This page is part of the man-pages (Linux kernel and C library
       user-space interface documentation) project.  Information about
       the project can be found at 
       ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report
       for this manual page, see
       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
       This page was obtained from the tarball man-pages-6.9.1.tar.gz
       fetched from
       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
       2024-06-26.  If you discover any rendering problems in this HTML
       version of the page, or you believe there is a better or more up-
       to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not
       part of the original manual page), send a mail to
       man-pages@man7.org

Linux man-pages 6.9.1          2024-05-02                        carg(3)

Pages that refer to this page: atan2(3),  atan(3),  complex(7)

HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH.