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   clog    ( 3 )

натуральный логарифм комплексного числа (natural logarithm of a complex number)

Имя (Name)

clog, clogf, clogl - natural logarithm of a complex number


Синопсис (Synopsis)

#include <complex.h>

double complex clog(double complex z); float complex clogf(float complex z); long double complex clogl(long double complex z);

Link with -lm.


Описание (Description)

These functions calculate the complex natural logarithm of z, with a branch cut along the negative real axis.

The logarithm clog() is the inverse function of the exponential cexp(3). Thus, if y = clog(z), then z = cexp(y). The imaginary part of y is chosen in the interval [-pi,pi].

One has:

clog(z) = log(cabs(z)) + I * carg(z)

Note that z close to zero will cause an overflow.


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 │ ├──────────────────────────────────────┼───────────────┼─────────┤ │clog(), clogf(), clogl() │ Thread safety │ MT-Safe │ └──────────────────────────────────────┴───────────────┴─────────┘


Стандарты (Conforming to)

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


Смотри также (See also)

cabs(3), cexp(3), clog10(3), clog2(3), complex(7)