[Numpy-discussion] Deprecate matrices in 1.15 and remove in 1.17?

[Marten van Kerkwijk]

Unlike for matrix, it is not so much a problem as an unclear use case
- the main thing they bring to structured dtype arrays is access by
attribute, which is slower than just doing getting the field by its
key.
Anyway, I don't think anybody is suggesting to remove them - they're
not a problem in the way matrix is, with its shape-mangling, etc.  --
Marten