The module `imaginary' provides complexnumbers. The functions provided are mainly corresponding to the `cmath' standard module.
exp(x [,err]) is the exponential function. The default value for err is defaultError.
expi(x [,err]) returns exp(i * x) where i is the imaginary unit and x must be a real number. The default value for err is defaultError.
log(x [,err]) returns the natural logarithm of x. There is one branch cut, from 0 along the negative real axis to -infinity, continuous from above. The default value for err is defaultError.