On Wed, Dec 23, 2009 at 10:30 AM, David Warde-Farley <d...@cs.toronto.edu> wrote: > On 23-Dec-09, at 10:34 AM, Anne Archibald wrote: > >> It's been a little while since I took a really close look at it, but >> I'll try to describe the problems I had. Chiefly I had problems with >> documentation - the only way I could figure out how to build >> additional gufuncs was monkey-see-monkey-do, just copying an existing >> one in an existing file and hoping the build system figured it out. It >> was also not at all clear how to, say, link to LAPACK, let alone >> decide based on input types which arguments to promote and how to call >> out to LAPACK. > > I tried to create a new generalized ufunc (a logsumexp to go with > logaddexp, so as to avoid all the needless exp's and log's that would > be incurred by logaddexp.reduce) and had exactly the same problem. I > did get it to build but it was misbehaving (returning an array of the > same size as the input) and I couldn't figure out quite why. I agree > that the documentation is lacking, but I think it's (rightly) a low > priority in the midst of the release candidate.
Thanks Anne (and Dave): it may seem to you to be "a bit silly to dream up an API without implementing anything," but I think it's useful to get these things "on the record" so to speak, and as a person charged with being especially concerned w/ the doc, it's particularly important for me to hear when its specific deficiencies are productivity blockers... >> The key idea would be that the "linear >> algebra dimensions" would always be the last one(s); this is fairly >> easy to arrange with rollaxis when it isn't already true, would tend >> to reduce copying on input to LAPACK, and is what the gufunc API >> wants. > > Would it actually reduce copying if you were using default C-ordered > arrays? Maybe I'm mistaken but I thought one almost always had to copy > in order to translate C to Fortran order except for a few functions > that can take row-ordered stuff. > > Otherwise, +1 all the way. ...and of course, discussing these things here begins a dialog that can be the beginning of getting these improvements made - not necessarily by you... :-) Thanks again, for humoring me DG _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion