clog, clogf, clogl

Retrieves the natural logarithm of a complex number, with a branch cut along the negative real axis.

Syntax

_Dcomplex clog(
   _Dcomplex z
);
_Fcomplex clog(
   _Fcomplex z
);  // C++ only
_Lcomplex clog(
   _Lcomplex z
);  // C++ only
_Fcomplex clogf(
   _Fcomplex z
);
_Lcomplex clogl(
   _Lcomplex z
);

Parameters

z
The base of the logarithm.

Return value

The natural logarithm of z. The result is unbounded along the real axis and in the interval [-iπ, +iπ] along the imaginary axis.

The possible return values are:

z parameter	Return value
Positive	The logarithm (base 10) of z
Zero	- INF
Negative	NaN
NaN	NaN
+ INF	+ INF

Remarks

Because C++ allows overloading, you can call overloads of clog that take and return _Fcomplex and _Lcomplex values. In a C program, clog always takes and returns a _Dcomplex value.

Requirements

Routine	C header	C++ header
clog, clogf, clogl	<complex.h>	<ccomplex>

For more compatibility information, see Compatibility.

See also

Alphabetical function reference
cexp, cexpf, cexpl
cpow, cpowf, cpowl
clog10, clog10f, clog10l