Nathaniel Smith wrote: > On Tue, Mar 12, 2013 at 9:25 PM, Nathaniel Smith <n...@pobox.com> wrote: >> On Mon, Mar 11, 2013 at 9:46 AM, Robert Kern <robert.k...@gmail.com> wrote: >>> On Sun, Mar 10, 2013 at 6:12 PM, Siu Kwan Lam <s...@continuum.io> wrote: >>>> My suggestion to overcome (1) and (2) is to allow the user to select >>>> between the two implementations (and possibly different algorithms in the >>>> future). If user does not provide a choice, we use the MT19937-32 by >>>> default. >>>> >>>> numpy.random.set_state("MT19937_64", …) # choose the 64-bit >>>> implementation >>> >>> Most likely, the different PRNGs should be different subclasses of >>> RandomState. The module-level convenience API should probably be left >>> alone. If you need to control the PRNG that you are using, you really >>> need to be passing around a RandomState instance and not relying on >>> reseeding the shared global instance. >> >> +1 >> >>> Aside: I really wish we hadn't >>> exposed `set_state()` in the module API. It's an attractive nuisance. >> >> And our own test suite is a serious offender in this regard, we have >> tests that fail if you run the test suite in a non-default order... >> https://github.com/numpy/numpy/issues/347 >> >> I wonder if we dare deprecate it? The whole idea of a global random >> state is just a bad one, like every other sort of global shared state. >> But it's one that's deeply baked into a lot of scientific programmers >> expectations about how APIs work... > > (To be clear, by 'it' here I meant np.random.set_seed(), not the whole > np.random API. Probably. And by 'deprecate' I mean 'whine loudly in > some fashion when people use it', not 'rip out in a few releases'. I > think.) > > -n
What do you mean that the idea of global shared state is a bad one? How would you prefer the API to look? An alternative is a stateless rng, where you have to pass it it's state on each invocation, which it would update and return. I hope you're not advocating that. _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion