Путеводитель по Руководству Linux

  User  |  Syst  |  Libr  |  Device  |  Files  |  Other  |  Admin  |  Head  |



   carg    ( 3 )

вычислить сложный аргумент (calculate the complex argument)

Имя (Name)

carg, cargf, cargl - calculate the complex argument

Синопсис (Synopsis)

#include <complex.h>

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

Link with -lm.


Описание (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)


Возвращаемое значение (Return value)

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

Версии (Versions)

These functions first appeared in glibc in version 2.1.

Атрибуты (Attributes)

For an explanation of the terms used in this section, see
       attributes(7).

┌──────────────────────────────────────┬───────────────┬─────────┐ │Interface Attribute Value │ ├──────────────────────────────────────┼───────────────┼─────────┤ │carg(), cargf(), cargl() │ Thread safety │ MT-Safe │ └──────────────────────────────────────┴───────────────┴─────────┘


Стандарты (Conforming to)

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

Смотри также (See also)

cabs(3), complex(7)