clog(3)                                               Library Functions Manual                                              clog(3)

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

LIBRARY
       Math library (libm, -lm)

SYNOPSIS
       #include <complex.h>

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

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 imag‐
       inary 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 were added in glibc 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 │
       └─────────────────────────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

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

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

Linux man-pages 6.03                                         2022-12-15                                                     clog(3)