Returns complex logarithm to the base e (2.718...) of
the complex argument x.
If z = x + iy, then
log(z) = log(abs(z)) + i arctan(y/x).
The arctangent ranges from -PI to +PI.
There are branch cuts along both the negative real and negative
imaginary axes. For pure imaginary arguments, use one of the
following forms, depending on which branch is required.
Natural logarithm, complex
Returns complex logarithm to the base e (2.718...) of the complex argument x.
If z = x + iy, then log(z) = log(abs(z)) + i arctan(y/x).
The arctangent ranges from -PI to +PI. There are branch cuts along both the negative real and negative imaginary axes. For pure imaginary arguments, use one of the following forms, depending on which branch is required.