carg

Section: C Library Functions (3)
Updated: 2022-12-15
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NAME

carg, cargf, cargl - calculate the complex argument  

LIBRARY

Math library (libm, -lm)  

SYNOPSIS

#include <complex.h>

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

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 in the range of [-pi,pi].  

VERSIONS

These functions were added in glibc 2.1.  

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).
InterfaceAttributeValue
carg(), cargf(), cargl() Thread safetyMT-Safe

 

STANDARDS

C99, POSIX.1-2001, POSIX.1-2008.  

SEE ALSO

cabs(3), complex(7)


 

Index

NAME
LIBRARY
SYNOPSIS
DESCRIPTION
RETURN VALUE
VERSIONS
ATTRIBUTES
STANDARDS
SEE ALSO

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Time: 17:20:08 GMT, March 28, 2024