Author mark.dickinson
Recipients mark.dickinson, rhettinger, steven.daprano
Date 2021-11-23.09:47:17
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Message-id <1637660837.66.0.611458091722.issue45876@roundup.psfhosted.org>
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I'm not sure this is worth worrying about. We already have a very tight error bound on the result: if `x` is a (positive) fraction and `y` is the closest float to x, (and assuming IEEE 754 binary64, round-ties-to-even, no overflow or underflow, etc.) then `math.sqrt(y)` will be in error by strictly less than 1 ulp from the true value √x, so we're already faithfully rounded. (And in particular, if the std. dev. is exactly representable as a float, this guarantees that we'll get that standard deviation exactly.)
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2021-11-23 09:47:17mark.dickinsonsetrecipients: + mark.dickinson, rhettinger, steven.daprano
2021-11-23 09:47:17mark.dickinsonsetmessageid: <1637660837.66.0.611458091722.issue45876@roundup.psfhosted.org>
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2021-11-23 09:47:17mark.dickinsoncreate