Reference

clogl(3)

complex natural logarithm functions

Part of clog(3).

NAME

clog, clogf and clogl – complex natural logarithm functions

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

The clog(), clogf(), and clogl() functions compute the complex natural logarithm of z. with a branch cut along the negative real axis .

RETURN VALUES

The clog() function returns the complex natural logarithm value, in the range of a strip mathematically unbounded along the real axis and in the interval [-I* , +I* ] along the imaginary axis. The function satisfies the relationship: clog(conj(z, Fc) = conj(clog(z, Fc).

ArgumentReturn valueComment
-0 + I*0- + I*Divide-by-zero exception
raised
+0 + I*0- + I*0Divide by zero exception
raised
x + I*+ + I*/2For finite x
x + I*+ I*Optionally raises invalid
floating-point exception
for finite x
- + I*y+ + I*For finite positive-signed y
+ + I*y+ + I*0For finite positive-signed y
- + I*+ + I*3/4
+ + I*+ + I*/4
+ I*+ + I*
+ I*y+ I*Optionally raises invalid
floating-point exception
for finite y
+ I*+ + I*
+ I*+ I*

SEE ALSO

complex(3), log(3), math(3)

STANDARDS

The clog(), cexpf(), and clogl() functions conform to ISO/IEC 9899:1999 (“ISO C99”).

History