Perhaps it is a slightly semantical discussion; but all fp calculations have 
errors, and there are always strategies for making them smaller. We just don't 
happen to like the error for this case; but rest assured it won't be hard to 
find new cases of 'blatantly wrong' results, no matter what accumulator is 
implemented. That's no reason to not try and be clever about it, but there 
isn't going to be an algorithm that is best for all possible inputs, and in the 
end the most important thing is that the algorithm used is specified in the 
docs.

-----Original Message-----
From: "Alan G Isaac" <alan.is...@gmail.com>
Sent: ‎25-‎7-‎2014 00:10
To: "Discussion of Numerical Python" <numpy-discussion@scipy.org>
Subject: Re: [Numpy-discussion] numpy.mean still broken for largefloat32arrays

On 7/24/2014 4:42 PM, Eelco Hoogendoorn wrote:
> This isn't a bug report, but rather a feature request.

I'm not sure statement this is correct.  The mean of a float32 array
can certainly be computed as a float32.  Currently this is
not necessarily what happens, not even approximately.
That feels a lot like a bug, even if we can readily understand
how the algorithm currently used produces it.  To say whether
it is a bug or not, don't we have to ask about the intent of `mean`?
If the intent is to sum and divide, then it is not a bug.
If the intent is to produce the mean, then it is a bug.

Alan Isaac
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