On Sat, Oct 27, 2018 at 6:37 PM Eric Wieser <wieser.eric+nu...@gmail.com> wrote:
> in order to be used prior to calling C or Fortran code that expected at > least a 1-d array > > I’d argue that the behavior for these functions should have just been to > raise an error saying “this function does not support 0d arrays”, rather > than silently inserting extra dimensions. As a bonus, that would push the > function developers to add support for 0d. Obviously we can’t make it do > that now, but what we can do is have it emit a warning in those cases. > > I think our options are: > > 1. Deprecate the entire function > 2. Deprecate and eventually(?) throw an error upon calling the > function on 0d arrays, with a message like *“in future using > ascontiguousarray to promote 0d arrays to 1d arrays will not be supported. > If promotion is intentional, use ascontiguousarray(atleast1d(x)) to silence > this warning and keep the old behavior, and if not use asarray(x, > order='C') to preserve 0d arrays”* > 3. Deprecate (future-warning) when passed 0d arrays, and eventually > skip the upcast to 1d. > If the calling code really needed a 1d array, then it will probably > fail, which is not really different to 2, but has the advantage that the > names are less surprising. > 4. Only improve the documentation > > My preference would be 3 > I'd go for 4, or alternatively for the warning in 2 (which can be left in place indefinitely). 1 is unwarranted, and 3 will change behavior which is worse than just warning or stopping to support existing behavior (= 2). Eric > > On Fri, 26 Oct 2018 at 17:35 Travis Oliphant <teoliph...@gmail.com> wrote: > > On Fri, Oct 26, 2018 at 7:14 PM Alex Rogozhnikov < >> alex.rogozhni...@yandex.ru> wrote: >> >>> > If the desire is to shrink the API of NumPy, I could see that. >>> >>> Very good desire, but my goal was different. >>> >> >>> > For some users this is exactly what is wanted. >>> >>> Maybe so, but I didn't face such example (and nobody mentioned those so >>> far in the discussion). >>> The opposite (according to the issue) happened. Mxnet example is >>> sufficient in my opinion. >>> >> >> I agree that the old motivation of APIs that would make it easy to create >> SciPy is no longer a major motivation for most users and even developers >> and so these reasons would not be very present (as well as why it wasn't >> even mentioned in the documentation). >> >> >>> Simple example: >>> x = np.zeros([]) >>> assert(x.flags.c_contiguous) >>> assert(np.ascontiguousarray(x).shape == x.shape) >>> >>> Behavior contradicts to documentation (shape is changed) and to name >>> (flags are saying - it is already c_contiguous) >>> >>> If you insist, that keeping ndmin=1 is important (I am not yet >>> convinced, but I am ready to believe your autority), >>> we can add ndmin=1 to functions' signatures, this way explicitly >>> notifying users about expected dimension. >>> >> >> I understand the lack of being convinced. This is ultimately a problem >> of 0-d arrays not being fully embraced and accepted by the Numeric >> community originally (which NumPy inherited during the early days). Is >> there a way to document functions that will be removed on a major version >> increase which don't print warnings on use? I would support this. >> > No, there's no such thing at the moment - the closest thing is https://github.com/numpy/numpy/wiki/Backwards-incompatible-ideas-for-a-major-release. I doubt we want such a thing anyway - removing functions without deprecation warnings first doesn't seem quite right. > >> I'm a big supporter of making a NumPy 2.0 and have been for several >> years. Now that Python 3 transition has happened, I think we could >> seriously discuss this. >> > I think it's more helpful to discuss goals and concrete plans for those, rather than a "NumPy 2.0" label. The latter never worked in the past, and not just because of lack of time/funding - it just means different things to different people. We now have a good start on what our major goals are ( http://www.numpy.org/neps/#roadmap), let's build on that. I'm trying to raise funding for maintenance and progress for NumPy and >> SciPy right now via Quansight Labs http://www.quansight.com/labs and I >> hope to be able to help find grants to support the wonderful efforts that >> have been happening for some time. >> > The NumPy grant and having Tyler/Matti/Stefan at BIDS is a great start to funded development; more and more diverse funding sources would be awesome. Cheers, Ralf >> While I'm thrilled and impressed by the number of amazing devs who have >> kept NumPy and SciPy going in mostly their spare time, it has created >> challenges that we have not had continuous maintenance funding to allow >> continuous paid development so that several people who know about the early >> decisions could not be retained to spend time on helping the transition. >> >> Your bringing the problem of mxnet devs is most appreciated. I will make >> a documentation PR. >> >> -Travis >> >> >> >> >>> Alex. >>> >>> >>> 27.10.2018, 02:27, "Travis Oliphant" <teoliph...@gmail.com>: >>> >>> What is the justification for deprecation exactly? These functions have >>> been well documented and have had the intended behavior of producing arrays >>> with dimension at least 1 for some time. Why is it unexpected to produce >>> arrays of at least 1 dimension? For some users this is exactly what is >>> wanted. I don't understand the statement that behavior with 0-d arrays is >>> unexpected. >>> >>> If the desire is to shrink the API of NumPy, I could see that. But, it >>> seems odd to me to remove a much-used function with an established behavior >>> except as part of a wider API-shrinkage effort. >>> >>> 0-d arrays in NumPy are a separate conversation. At this point, I think >>> it was a mistake not to embrace 0-d arrays in NumPy from day one. In some >>> sense 0-d arrays *are* scalars at least conceptually and for JIT-producing >>> systems that exist now and will be growing in the future, they can be >>> equivalent to scalars. >>> >>> The array scalars should become how you define what is *in* a NumPy >>> array making them true Python types, rather than Python 1-style "instances" >>> of a single "Dtype" object. You would then have 0-d arrays and these >>> Python "memory" types describing what is *in* the array. >>> >>> There is a clear way to do this, some of which has been outlined by >>> Nathaniel, and the rest I have an outline for how to implement. I can >>> advise someone on how to do this. >>> >>> -Travis >>> >>> >>> >>> >>> On Thu, Oct 25, 2018 at 3:17 PM Alex Rogozhnikov < >>> alex.rogozhni...@yandex.ru> wrote: >>> >>> Dear numpy community, >>> >>> I'm planning to depreciate np.asfortranarray and np.ascontiguousarray >>> functions due to their misbehavior on scalar (0-D tensors) with PR >>> #12244. >>> >>> Current behavior (converting scalars to 1-d array with single element) >>> - is unexpected and contradicts to documentation >>> - probably, can't be changed without breaking external code >>> - I believe, this was a cause for poor support of 0-d arrays in mxnet. >>> - both functions are easily replaced with asarray(..., order='...'), >>> which has expected behavior >>> >>> There is no timeline for removal - we just need to discourage from using >>> this functions in new code. >>> >>> Function naming may be related to how numpy treats 0-d tensors >>> specially, >>> and those probably should not be called arrays. >>> https://www.numpy.org/neps/nep-0027-zero-rank-arrarys.html >>> However, as a user I never thought about 0-d arrays being special and >>> being "not arrays". >>> >>> >>> Please see original discussion at github for more details >>> https://github.com/numpy/numpy/issues/5300 >>> >>> Your comments welcome, >>> Alex Rogozhnikov >>> >>> _______________________________________________ >>> NumPy-Discussion mailing list >>> NumPy-Discussion@python.org >>> https://mail.python.org/mailman/listinfo/numpy-discussion >>> >>> , >>> >>> _______________________________________________ >>> NumPy-Discussion mailing list >>> NumPy-Discussion@python.org >>> https://mail.python.org/mailman/listinfo/numpy-discussion >>> >>> _______________________________________________ >>> NumPy-Discussion mailing list >>> NumPy-Discussion@python.org >>> https://mail.python.org/mailman/listinfo/numpy-discussion >>> >> _______________________________________________ >> NumPy-Discussion mailing list >> NumPy-Discussion@python.org >> https://mail.python.org/mailman/listinfo/numpy-discussion >> > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@python.org > https://mail.python.org/mailman/listinfo/numpy-discussion >
_______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@python.org https://mail.python.org/mailman/listinfo/numpy-discussion
