Hi, On Tue, Apr 2, 2013 at 7:09 PM, <josef.p...@gmail.com> wrote: > On Tue, Apr 2, 2013 at 5:52 PM, Nathaniel Smith <n...@pobox.com> wrote: >> On Tue, Apr 2, 2013 at 10:21 PM, Matthew Brett <matthew.br...@gmail.com> >> wrote: >>>> This is like observing that if I say "go North" then it's ambiguous >>>> about whether I want you to drive or walk, and concluding that we need >>>> new words for the directions depending on what sort of vehicle you >>>> use. So "go North" means drive North, "go htuoS" means walk North, >>>> etc. Totally silly. Makes much more sense to have one set of words for >>>> directions, and then make clear from context what the directions are >>>> used for -- "drive North", "walk North". Or "iterate C-wards", "store >>>> F-wards". >>>> >>>> "C" and "Z" mean exactly the same thing -- they describe a way of >>>> unraveling a cube into a straight line. The difference is what we do >>>> with the resulting straight line. That's why I'm suggesting that the >>>> distinction should be made in the name of the argument. >>> >>> Could you unpack that for the 'ravel' docstring? Because these >>> options all refer to the way of unraveling and not the memory layout >>> that results. >> >> Z/C/column-major/whatever-you-want-to-call-it is a general strategy >> for converting between a 1-dim representation and a n-dim >> representation. In the case of memory storage, the 1-dim >> representation is the flat space of pointer arithmetic. In the case of >> ravel, the 1-dim representation is the flat space of a 1-dim indexed >> array. But the 1-dim-to-n-dim part is the same in both cases. >> >> I think that's why you're seeing people baffled by your proposal -- to >> them the "C" refers to this general strategy, and what's different is >> the context where it gets applied. So giving the same strategy two >> different names is silly; if anything it's the contexts that should >> have different names. > > And once we get into memory optimization (and avoiding copies and > preserving contiguity), it is necessary to keep both orders in mind, > is memory order in "F" and am I iterating/raveling in "F" order > (or slicing columns). > > I think having two separate keywords give the impression we can > choose two different things at the same time.
I guess it could not make sense to do this: np.ravel(a, index_order='C', memory_order='F') It could make sense to do this: np.reshape(a, (3,4), index_order='F, memory_order='F') but that just points out the inherent confusion between the uses of 'order', and in this case, the fact that you can only do: np.reshape(a, (3, 4), index_order='F') correctly distinguishes between the meanings. Best, Matthew _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
