Charles R Harris wrote: > > > On 3/24/07, *Travis Oliphant* <[EMAIL PROTECTED] > <mailto:[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.
Yes, thanks to a suggestion from Alan Isaac, this was implemented in PyMatrix (based on numarray and not yet converted to numpy). / served for one and // for the other. Regarding an additional multiply operator, I don't see the need for it. A matrix and and array are similar dut different animals. Colin W. We also > have both dot and tensordot, which raises the problem of interpretation > when ndim > 2. > > Chuck > > > > ------------------------------------------------------------------------ > > _______________________________________________ > Numpy-discussion mailing list > Numpy-discussion@scipy.org > http://projects.scipy.org/mailman/listinfo/numpy-discussion _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
