[SciPy-dev] Statistics Review progress
schofield at ftw.at
Thu Apr 13 05:10:42 CDT 2006
Travis Oliphant wrote:
> How about making the default minimize mean square error --- i.e
> division by N+1 for variance calculation :-)
Robert Kern wrote:
> I would implement varbiased() and var()
> def varbiased(a):
> return var_with_flag(a, bias=True)
> def var(a):
> return var_with_flag(a, bias=False)
> I *don't* want three versions of each of these functions.
If we really want just one version for the three cases with denominators
(n-1), n, and (n+1), I suggest we get rid of the boolean bias flag and
make it an integer flag instead, taking either -1 (default), 0, or +1.
A boolean flag would be clumsy, since it'd be true for both the n and
(n+1) cases, and we'd need yet another flag to distinguish between
these. And, as others have pointed out, bias=False would be an
inaccurate description of the std function.
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