Message242026
| Author |
tim.peters |
| Recipients |
mark.dickinson, rhettinger, serhiy.storchaka, tim.peters |
| Date |
2015年04月25日.22:04:24 |
| SpamBayes Score |
-1.0 |
| Marked as misclassified |
Yes |
| Message-id |
<1429999464.62.0.449352549469.issue24059@psf.upfronthosting.co.za> |
| In-reply-to |
| Content |
FYI, my results match Serhiy's, on Windows, under Pythons 3.4.2 and 2.7.8.
It's not surprising to me. Since IEEE 754 standardized sqrt, most vendors complied, delivering a square root "as if infinitely precise" with one anally correct rounding. But unless the platform pow() special-cases 0.5, that's going to involve a logarithm, multiplication, and exponentiation under the covers. pow() implementations usually fake some "extra precision" (else the worst-case errors can be horrendous), but it's still not always the same as single-rounding.
Raymond, I didn't understand this part: "It's odd because your two result as same number, just displayed differently." The output immediately following that showed they _are_ different numbers on your box too (the .hex() outputs differ by one in the last place). |
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