CLOG(3) Library Functions Manual CLOG(3)

clog — complex logarithm function

#include <complex.h>

double complex
clog(double complex z);

long double complex
clogl(long double complex z);

float complex
clogf(float complex z);

(z) returns the complex logarithm of z.

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

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

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

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

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

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

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

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

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

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

(±inf + NaN i) returns inf + NaN i.

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

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

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

cexp(3) log(3) complex(3)

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

December 11, 2006 BSD 4