On 3/24/07, Charles R Harris <[EMAIL PROTECTED]> wrote: > > > On 3/24/07, Travis Oliphant <[EMAIL PROTECTED]> wrote: > > Every so often the idea of new operators comes up because of the need to > > do both "matrix-multiplication" and element-by-element multiplication. > > > > I think this is one area where the current Python approach is not as > > nice because we have a limited set of operators to work with. > > > > One thing I wonder is if we are being vocal enough with the Python 3000 > > crowd to try and get additional operators into the language itself. > > > > What if we could get a few new operators into the language to help us. > > If we don't ask for it, it certainly won't happen. > > My experience is that the difficulty of using the '*' operator for both > > matrix multiplication and element-by-element multiplication depending on > > the class of the object is not especially robust. It makes it harder to > > write generic code, and we still haven't gotten everything completely > > right. > > > > It is somewhat workable as it stands, but I think it would be nicer if > > we could have some "meta" operator that allowed an alternative > > definition of major operators. Something like @* for example (just > > picking a character that is already used for decorators). > > Yes indeed, this is an old complaint. Just having an infix operator would be > an improvement: > > A dot B dot C > > Not that I am suggesting dot in this regard ;) In particular, it wouldn't > parse without spaces. What about division? Matlab has both / and \ for left > and right matrix division and something like that could call solve instead > of inverse, leading to some efficiencies. We also have both dot and > tensordot, which raises the problem of interpretation when ndim > 2. > > Chuck > I understand the convenience of more infix operators. And I sometimes think one should just be able to define new ones at will ....
On the other hand, I'm now playing the devil's advocate: A "math specific" language like Matlab has obviously an overwhelming need for a second set of matrix/array operators. However, a language -- as broadly used as -- Python might be just better off having a simple, concise and limited set of infix operators. I assume that this is the official argument. I got especially "worried" when being remember of the "\" right-to-left division operator. (As I said, it very useful to have in Matlab, and I wish sometimes we could add things like this). It is just important to keep the "con" - argument clearly in mind. I hope this helps the discussion. - Sebastian Haase _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
