[Numpy-tickets] [NumPy] #502: Unbiased estimates of variance/ std deviation
NumPy
numpy-tickets@scipy....
Wed Apr 18 01:23:28 CDT 2007
#502: Unbiased estimates of variance/ std deviation
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Reporter: pierregm | Owner: somebody
Type: enhancement | Status: new
Priority: low | Milestone:
Component: Other | Version: none
Severity: trivial | Keywords:
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Unbiased estimates of the variance and standard deviation are used far
more often than their biased counterparts. Currently, the var/std
methods/functions return biased estimates. Unbiased estimates can be
obtained simply by multiplying the variance by n/float(n-1) (where n is
the size of the array along a particular axis). This extra step (and the
test on n it implies) becomes quickly tedious when used repeatedly.
I suggest the introduction of 2 new methods (and the corresponding
functions), varu and stdu, that would give direct access to the unbiased
estimates.
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Ticket URL: <http://projects.scipy.org/scipy/numpy/ticket/502>
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