On 19/09/2007, Travis E. Oliphant <oliphant@enthought.com> wrote:
Anne Archibald wrote:
vectorize, of course, is a good example of my point above: it really just loops, in python IIRC, but conceptually it's extremely handy for doing exactly what the OP wanted. Unfortunately vectorize() does not yield a sufficiently ufunc-like object to support .outer(), as that would be extremely tidy.
I'm not sure what you mean by sufficiently ufunc-like. In fact, vectorize is a ufunc (it's just an object-based one). Thus, it should produce what you want (as long as you use newaxis so that the broadcasting is done). If you just want it to support the .outer method that could be easily done (as under the covers is a real ufunc).
I just over-looked adding these methods to the result of vectorize. The purpose of vectorize is to create a ufunc out of a scalar-based function, so I don't see any problem in giving them the methods of ufuncs as well (as long as the signature is right --- 2 inputs and 1 output).
Ah. You got it in one: I was missing the methods. It would be handy to have them back, not least because then I could just remember the rule "all binary ufuncs have .outer()". Do ternary ufuncs support outer()? It would presumably just generate a higher-rank array, for example U.outer(arange(10),arange(11),arange(12)) would produce an array of shape (10,11,12)... maybe there aren't any ternary ufuncs yet, apart from the ones that are generated by vectorize(). I suppose ix_ provides an alternative, so that you could have def outer(self,*args): return self(ix_(*args)) Still, I think for conceptual tidiness it would be nice if the ufuncs vectorize() makes supported the methods. Thanks, Anne