[Numpy-discussion] Computing Simple Statistics When Only they Frequency Distribution is Known

josef.pktd@gmai... josef.pktd@gmai...
Fri Nov 27 21:14:25 CST 2009


On Fri, Nov 27, 2009 at 9:47 PM, Wayne Watson
<sierra_mtnview@sbcglobal.net> wrote:
> How do I compute avg, std dev, min, max and other simple stats if I only
> know the frequency distribution?

If you are willing to assign to all observations in a bin the value at
the bin midpoint, then you could do it with weights in the statistics
calculations. However, numpy.average is, I think, the only statistic
that takes weights. min max are independent of weight, but std and var
need to be calculated indirectly.

If you need more stats with weights, then the attachment in
http://projects.scipy.org/scipy/ticket/604  is a good start.

Josef


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