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man:cargf

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.`

`     cabs(3), complex(7)`

COLOPHON

```     This page is part of release 4.16 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)` 