v7 man page for clog

CLOG(3) 						     Linux Programmer's Manual							   CLOG(3)

NAME

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

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.

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.

VERSIONS

       These functions first appeared in glibc in version 2.1.

ATTRIBUTES

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

       +-------------------------+---------------+---------+
       |Interface		 | Attribute	 | Value   |
       +-------------------------+---------------+---------+
       |clog(), clogf(), clogl() | Thread safety | MT-Safe |
       +-------------------------+---------------+---------+
CONFORMING TO

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

SEE ALSO

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

COLOPHON

       This page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and  the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

								    2017-09-15								   CLOG(3)