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)
