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¶

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.

CONFORMING TO¶

C99.

SEE ALSO¶

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

COLOPHON¶

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