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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 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 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)