Hi All, Having just had a look at functions where astropy's quantities are silently converted to ndarray, I came across some that, in principle, are easy to solve, yet for which, as always, there is a worry about backward compatibility. So, the question arises what to do. As a specific example, consider `np.outer` which is defined in `numeric.py` and boils down to multiply(a.ravel()[:, newaxis], b.ravel()[newaxis,:], out) Since multiply is fine with subclasses, all should be well, except that before it is called, there are `a = asarray(a)` and `b = asarray(b)` statements, which mean subclasses are lost. Obviously, in this case, a simple fix would be to use `asanyarray` instead, but ideally, similar routines behave similarly and hence one would also want to change `np.inner` and `np.dot` (and perhaps more)... Hence, before doing anything, I thought I would ask whether: 1. Such changes are or are not too risky for backward compatibility; 2. If so, whether, given that `np.dot` can be caught using `__numpy_ufunc__`, one should perhaps allow functions such as `outer` also to be passed through that? All the best, Marten