Well, I can tell you why it needs to be backward compatible! I use random numbers fairly frequently, and to unit test them I set a specific seed and then make sure I get the same answers.
If your change went in (and I were using numpy normal distributions, which I am not) then my tests would break. Particularly, you'd have the unfixable problem that it would be impossible to write tests for your code that worked regardless of the version of numpy that was installed. Yes, I agree that in your use case, this is powerfully unfortunate, and prevents you from making a change that would otherwise benefit everyone. The three ways to do this would be the following: - Add a new parameter to the function call, say, faster=False, which you set True to get the new behavior - Add a global flag somewhere you set to get the new behavior everywhere - Create a new function called normal_faster or some such All of these are ugly for obvious reasons. On Sat, Feb 6, 2021 at 10:33 AM <camel-...@protonmail.com> wrote: > I tried to implement a different implementation of the ziggurat method for > generating standard normal distributions that is about twice as fast and > uses 2/3 of the memory than the old one. > I tested the implementation separately and am very confident it's correct, > but it does fail 28 test in coverage testing. > Checking the testing code I found out that all the failed tests are inside > TestRandomDist which has the goal of "Make[ing] sure the random > distribution returns the correct value for a given seed". Why would this be > needed? > The only explanation I can come up with is that it's standard_normal is, > in regards to seeding, required to be backwards compatible. If that's the > case how would, could one even implement a new algorithm? > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@python.org > https://mail.python.org/mailman/listinfo/numpy-discussion > -- /t PGP Key: https://flowcrypt.com/pub/tom.ritchf...@gmail.com *https://tom.ritchford.com <https://tom.ritchford.com>* *https://tom.swirly.com <https://tom.swirly.com>*
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