On Wed, Aug 6, 2014 at 5:33 PM, Nathaniel Smith <n...@pobox.com> wrote:
> On Thu, Aug 7, 2014 at 12:24 AM, Charles R Harris > <charlesr.har...@gmail.com> wrote: > > > > On Wed, Aug 6, 2014 at 4:57 PM, Nathaniel Smith <n...@pobox.com> wrote: > >> > >> On Wed, Aug 6, 2014 at 4:32 PM, Charles R Harris > >> <charlesr.har...@gmail.com> wrote: > >> > Should also mention that we don't have the ability to operate on > stacked > >> > vectors because they can't be identified by dimension info. One > >> > workaround > >> > is to add dummy dimensions where needed, another is to add two flags, > >> > row > >> > and col, and set them appropriately. Two flags are needed for backward > >> > compatibility, i.e., both false is a traditional array. > >> > >> It's possible I could be convinced to like this, but it would take a > >> substantial amount of convincing :-). It seems like a pretty big > >> violation of orthogonality/"one obvious way"/etc. to have two totally > >> different ways of representing row/column vectors. > >> > > > > The '@' operator supports matrix stacks, so it would seem we also need to > > support vector stacks. The new addition would only be effective with the > '@' > > operator. The main problem I see with flags is that adding them would > > require an extensive audit of the C code to make sure they were > preserved. > > Another option, already supported to a large extent, is to have row and > col > > classes inheriting from ndarray that add nothing, except for a possible > new > > transpose type function/method. I did mock up such a class just for fun, > and > > also added a 'dyad' function. If we really don't care to support stacked > > vectors we can get by without adding anything. > > It's possible you could convince me that this is a good idea, but I'm > starting at like -0.95 :-). Wouldn't it be vastly simpler to just have > np.linalg.matvec, matmat, vecvec or something (each of which are > single-liners in terms of @), rather than deal with two different ways > of representing row/column vectors everywhere? > > Sure, but matvec and vecvec would not be supported by '@' except when vec was 1d because there is no way to distinguish a stack of vectors from a matrix or a stack of matrices. Chuck
_______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
