Message395399
BTW, to forestall questions about adding cmath.cbrt: it's not obvious how to extend the real cube root function to a complex cube root, so it might make sense to wait for actual use-cases before doing so.
The issue is that the most natural way to define a complex cube root would use a branch cut along the negative real axis (the same branch cut that cmath.sqrt and cmath.log use). But then the principal branch would *not* be an extension of math.cbrt: it would return non-real values on the negative real axis. (The *real* cube roots of negative numbers would fall on the two non-principal branches.)
See for example https://math.stackexchange.com/questions/71775/extending-the-cube-root-function-to-mathbbc |
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2021-06-09 09:02:58 | mark.dickinson | set | recipients:
+ mark.dickinson, lemburg, rhettinger, stutzbach, serhiy.storchaka, AjithRamachandran |
2021-06-09 09:02:57 | mark.dickinson | set | messageid: <1623229377.99.0.97367824118.issue44357@roundup.psfhosted.org> |
2021-06-09 09:02:57 | mark.dickinson | link | issue44357 messages |
2021-06-09 09:02:57 | mark.dickinson | create | |
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