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   carg    ( 3 )

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Имя (Name)

carg, cargf, cargl - calculate the complex argument

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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.

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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)

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Возвращаемое значение (Return value)

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

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Версии (Versions)

These functions first appeared in glibc in version 2.1.

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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 │
       └──────────────────────────────────────┴───────────────┴─────────┘

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Стандарты (Conforming to)

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

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Смотри также (See also)

cabs(3), complex(7)

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