clog, clogf, clogl - natural logarithm of a complex number
double complex clog(double complex z);
float complex clogf(float complex z);
long double complex clogl(long double complex z);
Link with -lm
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
(3). Thus, if y = clog(z)
z = cexp(y)
. The imaginary part of y
is chosen in
the interval [-pi,pi].
clog(z) = log(cabs(z)) + I * carg(z)
Note that z
close to zero will cause an overflow.
These functions first appeared in glibc in version 2.1.
For an explanation of the terms used in this section, see attributes
|clog (), clogf (), clogl ()
C99, POSIX.1-2001, POSIX.1-2008.