Richard Damon wrote: > If you thing of the Standard Deviation being the Root Mean Norm2 of the > deviations, it has a very similar meaning as to over the reals, a > measure of the "spread" of the values. NumPy appears to handle this: http://docs.scipy.org/doc/numpy/reference/generated/numpy.std.html See the comment on that page about complex numbers. So yes, it is meaningful and apparently people use it. -- Greg