On Do, 2015-09-24 at 13:14 +0200, Sebastian Berg wrote: > On Do, 2015-09-24 at 03:26 -0700, Stefan van der Walt wrote: > > On 2015-09-24 00:17:33, Jens Jørgen Mortensen <je...@fysik.dtu.dk> wrote: > > > jensj@jordan:~$ python > > > Python 2.7.9 (default, Apr 2 2015, 15:33:21) > > > [GCC 4.9.2] on linux2 > > > Type "help", "copyright", "credits" or "license" for more information. > > > >>> import numpy as np > > > >>> a = np.zeros((2, 2, 2)) > > > >>> b = np.zeros((2, 2, 2)) > > > >>> a[0, 0] = 7 > > > >>> b[0, 0] = 6 > > > >>> np.vdot(a[:, :, 0], b[:, :, 0]).real > > > 84.0 > > > >>> np.__version__ > > > '1.10.0rc1' > > > > > > The result should be 42. This is on Ubuntu 15.04. > > > > The input is not supposed to be matrices—but the docstring specifically > > states that those should then be ravelled, so this is indeed a bug. > > > > If I bisected correctly, the problematic change is this one: > > > > Hmmm, unless we want to make sure that the output of ravel is always > contiguous (which would be a difference from `.reshape(-1)`. > It would be a bit safer, and not a useless feature maybe, since we can > point to `.reshape(-1)` as well for those who do not care. >
So to say, I am not quite sure yet. But if anyone is even a tiny bit nervous about doing less copying/not guaranteeing a contiguous result, lets change the definition of ravel to return a contiguous array always (and document it pointing people to reshape if they have no need for it). > As far as I can see a contiguous output was not guaranteed for > "keeporder", but nobody probably ever used keeporder.... > > - Sebastian > > > > > > commit 44877b36870ec2a0505c536a30b9fbf06a414c17 > > Author: Sebastian Berg <sebast...@sipsolutions.net> > > Date: Wed Sep 3 18:33:06 2014 +0200 > > > > ENH: Allow ravel to reshape in place when possible > > > > This fixes a lot of corner cases in reshape 'K' when the array > > is not contiguous in the first place, it was previously never > > ravelled in place. > > > > Closes gh-5033 > > > > > > Stéfan > > _______________________________________________ > > NumPy-Discussion mailing list > > NumPy-Discussion@scipy.org > > https://mail.scipy.org/mailman/listinfo/numpy-discussion > > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > https://mail.scipy.org/mailman/listinfo/numpy-discussion
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