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

## NAME         top

```       carg, cargf, cargl - calculate the complex argument
```

## 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 the range of [-pi,pi].
```

## VERSIONS         top

```       These functions first appeared in glibc in version 2.1.
```

## 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 │
└─────────────────────────┴───────────────┴─────────┘
```

## CONFORMING TO         top

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

```       cabs(3), complex(7)
```

## COLOPHON         top

```       This page is part of release 5.02 of the Linux man-pages project.  A
description of the project, information about reporting bugs, and the