CLOG(3)

NAME
clog - complex logarithm function

SYNOPSIS
#include <complex.h>
double complex
clog(double complex z);
long double complex
clogl(long double complex z);
float complex
clogf(float complex z);

DESCRIPTION
clog(z) returns the complex logarithm of z.

clog(conj(z)) = conj(clog(z)), for all complex floating-point numbers z.

SPECIAL VALUES
The conjugate symmetry of clog() is used to abbreviate the specification of special values.

clog(-0 + 0i) returns -inf + Pi i and raises the divide-by-zero flag.

clog(0 + 0i) returns -inf + 0i and raises the divide-by-zero flag.

clog(x + inf i) returns inf + Pi/2 i, for finite x.

clog(x + NaN i) returns NaN + NaN i.

clog(-inf + yi) returns inf + Pi i, for finite positive y.

clog(inf + yi) returns inf + 0i, for finite positive y.

clog(-inf + inf i) returns inf + 3Pi/4 i.

clog(inf + inf i) returns inf + Pi/4 i.

clog(ħinf + NaN i) returns inf + NaN i.

clog(NaN + yi) returns NaN + NaN i, for finite y.

clog(NaN + inf i) returns inf + NaN i.

clog(NaN + NaN i) returns NaN + NaN i.

NOTES

SEE ALSO
cexp(3) log(3) complex(3)

STANDARDS
The clog() function conforms to ISO/IEC 9899:2011.