On Sun, Oct 12, 2014 at 9:13 PM, Nathaniel Smith <n...@pobox.com> wrote:
> On Sun, Oct 12, 2014 at 5:14 PM, Sebastian <se...@sebix.at> wrote: > > > > On 2014-10-12 16:54, Warren Weckesser wrote: > >> > >> > >> On Sun, Oct 12, 2014 at 7:57 AM, Robert Kern <robert.k...@gmail.com > >> <mailto:robert.k...@gmail.com>> wrote: > >> > >> On Sat, Oct 11, 2014 at 11:51 PM, Warren Weckesser > >> <warren.weckes...@gmail.com <mailto:warren.weckes...@gmail.com>> > >> wrote: > >> > >> > A small wart in this API is the meaning of > >> > > >> > shuffle(a, independent=False, axis=None) > >> > > >> > It could be argued that the correct behavior is to leave the > >> > array unchanged. (The current behavior can be interpreted as > >> > shuffling a 1-d sequence of monolithic blobs; the axis argument > >> > specifies which axis of the array corresponds to the > >> > sequence index. Then `axis=None` means the argument is > >> > a single monolithic blob, so there is nothing to shuffle.) > >> > Or an error could be raised. > >> > > >> > What do you think? > >> > >> It seems to me a perfectly good reason to have two methods instead > of > >> one. I can't imagine when I wouldn't be using a literal True or > False > >> for this, so it really should be two different methods. > >> > >> > >> > >> I agree, and my first inclination was to propose a different method > >> (and I had the bikeshedding conversation with myself about the name: > >> "disarrange", "scramble", "disorder", "randomize", "ashuffle", some > >> other variation of the word "shuffle", ...), but I figured the first > >> thing folks would say is "Why not just add options to shuffle?" So, > >> choose your battles and all that. > >> > >> What do other folks think of making a separate method > > I'm not a fan of more methods with similar functionality in Numpy. It's > > already hard to overlook the existing functions and all their possible > > applications and variants. The axis=None proposal for shuffling all > > items is very intuitive. > > > > I think we don't want to take the path of matlab: a huge amount of > > powerful functions, but few people know of their powerful possibilities. > > I totally agree with this principle, but I think this is an exception > to the rule, b/c unfortunately in this case the function that we *do* > have is weird and inconsistent with how most other functions in numpy > work. It doesn't vectorize! Cf. 'sort' or how a 'shuffle' gufunc > (k,)->(k,) would work. Also, it's easy to implement the current > 'shuffle' in terms of any 1d shuffle function, with no explicit loops, > Warren's disarrange requires an explicit loop. So, we really > implemented the wrong one, oops. What this means going forward, > though, is that our only options are either to implement both > behaviours with two functions, or else to give up on have the more > natural behaviour altogether. I think the former is the lesser of two > evils. > > Regarding names: shuffle/permutation is a terrible naming convention > IMHO and shouldn't be propagated further. We already have a good > naming convention for inplace-vs-sorted: sort vs. sorted, reverse vs. > reversed, etc. > > So, how about: > > scramble + scrambled shuffle individual entries within each > row/column/..., as in Warren's suggestion. > > shuffle + shuffled to do what shuffle, permutation do now (mnemonic: > these break a 2d array into a bunch of 1d "cards", and then shuffle > those cards). > > permuted remains indefinitely, with the docstring: "Deprecated alias > for 'shuffled'." > > That sounds good to me. (I might go with 'randomize' instead of 'scramble', but that's a second-order decision for the API.) Warren -n > > -- > Nathaniel J. Smith > Postdoctoral researcher - Informatics - University of Edinburgh > http://vorpus.org > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion >
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