On Tue, Feb 14, 2012 at 9:14 AM, Pierre <pierre.guil...@gmail.com> wrote: > oh and a related question -- been wondering about this for a while : > if i put all this in a foo.spyx file, i usually do "load foo.spyx". It > works, but compiles every time! how do you just load the compiled > version? > and what about import it like a module, using > foo.function() ?
You can do all that -- it just costs you about 2 hours of background education and practice. You have to use a .pyx file, probably a setup.py file, and follow the standard instructions at cython.org: http://docs.cython.org/src/quickstart/index.html -- William > > On 14 fév, 18:11, Pierre <pierre.guil...@gmail.com> wrote: >> Hey, thanks for all the responses. I use Cython occasionally, but i >> tend to restrict myself to basic C types and simple functions which do >> not import anything -- it seems I can learn an awful lot by studying >> your examples! >> >> Can i ask the following questions about Jason's code? >> >> ** why so you 'import' CDF while you 'cimport' ComplexDoubleElement? >> what is the difference? >> >> ** and why do these imports anyway, are they necessary for "cdef >> complex..." to work? >> >> ** I didn't know PY_NEW. What is the difference between res= >> PY_NEW(Matrix2) and simply res= Matrix2(0,0,0,0) (say) ? and what >> about using PY_NEW with a class that *requires* parameters to its >> __init__? >> >> ** more generally, is there a Cython tutorial that would be (just) >> sufficiently advanced to cover such an example? >> >> thanks! >> Pierre >> >> On 13 fév, 20:13, William Stein <wst...@gmail.com> wrote: >> >> >> >> >> >> >> >> > On Mon, Feb 13, 2012 at 11:07 AM, Jason Grout >> >> > <jason-s...@creativetrax.com> wrote: >> > > On 2/13/12 12:41 PM, William Stein wrote: >> >> > >> On Mon, Feb 13, 2012 at 10:29 AM, Robert Bradshaw >> > >> <rober...@math.washington.edu> wrote: >> >> > >>> On Mon, Feb 13, 2012 at 10:06 AM, William Stein<wst...@gmail.com> >> > >>> wrote: >> >> > >>>> On Mon, Feb 13, 2012 at 9:59 AM, Pierre<pierre.guil...@gmail.com> >> > >>>> wrote: >> >> > >>>>> I see. Well I *do* have hundreds of 2x2 matrices to multiply out so >> > >>>>> i'm better off storing them as numpy matrices throughout... thanks >> > >>>>> for >> > >>>>> your explanations though. >> >> > >>>>> Pierre >> >> > >>>> You might consider using Cython and writing a custom 2x2 matrix class. >> > >>>> It wouldn't be difficult... so I'll write one right now and respond >> > >>>> with the benchmarks. >> >> > >> Here it is: http://480.sagenb.org/home/pub/97/ >> >> > >> I ended up using GSL's complex matrix data type and the BLAS level 3 >> > >> routine to do the multiplication. I did not add any other >> > >> convenience functions to the class, so some more will probably be >> > >> needed for your application. >> >> > > I'm curious why you didn't just store the 4 complex numbers in C. >> >> > I was concerned about "numerical stability" and figured BLAS would >> > deal with that. But maybe that doesn't matter. >> >> > Most importantly, I forgot about Cython's complex type, which I now >> > remember Robert Bradshaw wrote for his thesis work. I wasn't looking >> > forward to writing your line: >> >> > res.m00=self.m00*right.m00+self.m01*right.m10 >> >> > but against the gsl library. But using the cython type in complex, >> > you get the above at C speed with easy notation, which is pretty >> > awesome. >> >> > > I tried >> > > it and got a much bigger speedup: 17x faster than numpy and 150x faster >> > > than >> > > Sage. Seehttp://sagenb.org/home/pub/4303/ >> >> > Nice. >> >> > > Thanks, >> >> > > Jason >> >> > > -- >> > > To post to this group, send email to sage-support@googlegroups.com >> > > To unsubscribe from this group, send email to >> > > sage-support+unsubscr...@googlegroups.com >> > > For more options, visit this group at >> > >http://groups.google.com/group/sage-support >> > > URL:http://www.sagemath.org >> >> > -- >> > William Stein >> > Professor of Mathematics >> > University of Washingtonhttp://wstein.org > > -- > To post to this group, send email to sage-support@googlegroups.com > To unsubscribe from this group, send email to > sage-support+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/sage-support > URL: http://www.sagemath.org -- William Stein Professor of Mathematics University of Washington http://wstein.org -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
