On 12 Dec 2008, at 1:33 , Joris De Ridder wrote: > I implemented the same function using C++ & ctypes, and the latter > function turns out to be about 100 times faster than the cython one, > for a 500x500 image, and dx,dy = 5,5. This surprises me, because of > the simplicity of the function. I checked the C file, and also the > translation of the maxfilter() function in C is quite simple. The > bulk of the time is of course spent in the loops, and the only > bottleneck that I can see is accessing the numpy arrays. Is there > anything I can do in Cython to speed that up?
My statement turned out to be wrong: I misread the unit of the timing. :-/ Cython took 168 ms, ctypes+Cpp took 1.41 s. Prejudiced about the speed of C++, I misread the latter as 1.41 ms. So, it turns out that Cython was actually 10 times faster! I'm still a bit puzzled about this difference, but it's on the ctypes side I have to look, not on the cython side. Thanks for the responses, and sorry for the noise. Joris Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm _______________________________________________ Cython-dev mailing list [email protected] http://codespeak.net/mailman/listinfo/cython-dev
