On Sat, 2008-08-16 at 22:03 -0700, Fernando Perez wrote: > Hi all, > > [ please keep all replies to this only on the numpy list. I'm cc'ing > the scipy ones to make others aware of the topic, but do NOT reply on > those lists so we can have an organized thread for future reference] > > In the Python-dev mailing lists, there were recently two threads > regarding the possibility of adding to the language new multiplication > operators (amongst others). This would allow one to define things > like an element-wise and a matrix product for numpy arrays, for > example: > > http://mail.python.org/pipermail/python-dev/2008-July/081508.html > http://mail.python.org/pipermail/python-dev/2008-July/081551.html > > It turns out that there's an old pep on this issue: > > http://www.python.org/dev/peps/pep-0225/ > > which hasn't been ruled out, simply postponed. At this point it seems > that there is room for some discussion, and obviously the input of the > numpy/scipy crowd would be very welcome. I volunteered to host a BOF > next week at scipy so we could collect feedback from those present, > but it's important that those NOT present at the conference can > equally voice their ideas/opinions. > > So I wanted to open this thread here to collect feedback. We'll then > try to have the bof next week at the conference, and I'll summarize > everything for python-dev. Obviously this doesn't mean that we'll get > any changes in, but at least there's interest in discussing a topic > that has been dear to everyone here. > > Cheers, > > f
As one of the original author behind the PEP225, I think this is an excellent idea. (BTW, thanks for resurrecting this old PEP :-) and considering it useful :-) :-) ). I think I do not need to speak to much for the PEP, telling that I did not change my mind should be enough ;-)...but still, I can not resist adding a few considerations: Demands for Elementwise operators and/or matrix product operator is likely to resurface from time to time on Python-dev or Python-idea, given that this is a central feature of Matlab and Matlab is a de-facto standard when it comes to numeric-oriented interpreted languages (well, at least in the engineering world, it is in my experience the biggest player by far). At the time of the original discussion on python-dev and of PEP225 redaction , I was new to Python and fresh from Matlab, and the default behavior of elementwise-product annoyed me a lot. Since then, I have learned to appreciate the power of numpy broadcast (Use it extensively in my code :-) ), so the default dehavior do not annoy me anymore... But I still feel that 2 sets of operator would be very useful ( especially in some code which implement directly heavy linear algebra formula), the only thing where my point of view has changed is that I now think that the Matlab way ( defining * as matrix product and .* as elementwise product) is not necessarily the best choice, the reverse choice is as valid... Given the increasing success of Python as a viable alternative, I think that settling the Elementwise operator issue is probably a good idea. Especially as the Python 3000 transition is maybe a good time to investigate syntax changes/extension. > > I don't think so, but given that pep 225 exists and is fully fleshed > out, I guess it should be considered the starting point of the > discussion for reference. This doesn't mean that modifications to it > can't be suggested, but that I'm assuming python-dev will want that as > the reference point. For something as big as this, they would > definitely want to work off a real pep. > > Having said that, I think all ideas are fair game at this point. I > personally would like to see it happen, but if not I'd like to see a > final pronouncement on the matter rather than seeing pep 225 deferred > forever. > I agree 100%. Keeping PEP 225 in limbo is the worst situation imho, given that the discussion about elementwise operator (or matrix product) keep showing again and again, having a final decision (even if negative) would be better. And as I said above, I feel the timing is right for this final decision... Best regards, Greg. _______________________________________________ Numpy-discussion mailing list [email protected] http://projects.scipy.org/mailman/listinfo/numpy-discussion
