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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