Hi all, I would like to/lean to going ahead with adding these. And in some discussions I think that was basically the decision, so that is the default currently.
But, I am not sure that nobody had serious disagreement about it (or maybe the conjugation part, although I think it drops out of the existing vecdot). I am more seriously considering whether we should only add them to the `numpy.linalg` namespace, while `matmul` and `vecdot` are in both `numpy` and `numpy.linalg`. (A bit tedious/surprising, but if not used much OK with the "See Also" section) - Sebastian On Tue, 2024-01-23 at 17:07 -0500, Marten van Kerkwijk wrote: > Hi All, > > I have a PR [1] that adds `np.matvec` and `np.vecmat` gufuncs for > matrix-vector and vector-matrix calculations, to add to plain > matrix-matrix multiplication with `np.matmul` and the inner vector > product with `np.vecdot`. They call BLAS where possible for speed. > I'd like to hear whether these are good additions. > > I also note that for complex numbers, `vecmat` is defined as `x†A`, > i.e., the complex conjugate of the vector is taken. This seems to be > the > standard and is what we used for `vecdot` too (`x†x`). However, it is > *not* what `matmul` does for vector-matrix or indeed vector-vector > products (remember that those are possible only if the vector is > one-dimensional, i.e., not with a stack of vectors). I think this is > a > bug in matmul, which I'm happy to fix. But I'm posting here in part > to > get feedback on that. > > Thanks! > > Marten > > [1] https://github.com/numpy/numpy/pull/25675 > > p.s. Separately, with these functions available, in principle these > could be used in `__matmul__` (and thus for `@`) and the > specializations > in `np.matmul` removed. But that can be a separate PR (if it is > wanted > at all). > _______________________________________________ > NumPy-Discussion mailing list -- numpy-discussion@python.org > To unsubscribe send an email to numpy-discussion-le...@python.org > https://mail.python.org/mailman3/lists/numpy-discussion.python.org/ > Member address: sebast...@sipsolutions.net _______________________________________________ NumPy-Discussion mailing list -- numpy-discussion@python.org To unsubscribe send an email to numpy-discussion-le...@python.org https://mail.python.org/mailman3/lists/numpy-discussion.python.org/ Member address: arch...@mail-archive.com
