I think I see your point, that the module is intended for the most basic
features, but I would argue that correlation is one of such "most basic"
statistics.

Correlation and covariance can be thought as equivalents for standard
deviation and variance, but when we are talking about pairs of variables.
Moreover it is probably used much more often then things like geometric or
harmonic mean, that are implemented in the package. Covariance is probably
more esoteric for most non-statisticians, but in my PR (
https://github.com/python/cpython/pull/16813 ) I implemented it for
completeness and as a helper function for the correlation coefficient.

TL;DR those are basic statistics. They would make the module much more
helpful, since the basic statistics could be calculated using base python
w/o external libraries. They are also trivial to implemented (done this in
PR) and do not need much more maintenance then the other functionalities in
the module.

Tim

śr., 16 paź 2019 o 02:50 Raymond Hettinger <report@bugs.python.org>
napisał(a):

>
> Raymond Hettinger <raymond.hettinger@gmail.com> added the comment:
>
> These two functions are right on the boundary edge of what the statistics
> module is trying to do, """The module is not intended to be a competitor to
> third-party libraries such as NumPy, SciPy, or proprietary full-featured
> statistics packages aimed at professional statisticians such as Minitab,
> SAS and Matlab. It is aimed at the level of graphing and scientific
> calculators."""
>
> It is debatable which side of the boundary they belong to. MS Excel has
> both of these functions, but it isn't a given that a scientific calculator
> would have them.
>
> Also, the current functions require only high-school level knowledge, but
> these two require more skill to learn, use, and interpret.
>
> ----------
> assignee:  -> steven.daprano
> nosy: +rhettinger, steven.daprano
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <https://bugs.python.org/issue38490>
> _______________________________________
>