On Wednesday, October 2, 2013 8:26:59 PM UTC+2, Ondřej Čertík wrote: > > The problem with Cython is that I am not able to make it as fast as > CSymPy in C++, > and I tried: > > https://github.com/certik/sympyx/blob/master/sympy_pyx.pyx > > The reason is that to truly nail the speed, one needs to use special > dictionary implementation, > tweak hashing functions, reference counting, memory allocators etc. > C++ allows to play with all that, while > having a reasonably high level syntax. In Cython one has to use Python > types like hashes/dicts ---- or resort > to effectively writing a pure C code --- either way, it becomes > overall more complex than just writing > things in C++ by hand. So I'll be happy to be proven wrong, but so far > C++ is a clear winner in terms of speed. > > Besides speed, I came to appreciate having just one language and write > everything in it. Much simpler to maintain > and master. With your sympy2cython approach, you need to master > Python, SymPy code, the sympy2cython > tool, Cython, C and Python C/API intricacies. That's a lot of layers. > The reason to do this is speed, otherwise > we can just use SymPy --- but to nail speed, you need to master all > these layers extremely well, and it might > still not be enough --- i.e. I think I know Cython and Python C/API > reasonably well, but I don't know how to > make the Cython code above as fast as CSymPy. In C++, on the other > hand, you can really nail the speed and it is > just one language to master and maintain. > > Ondrej >
OK, maybe for speed purposes C++ handwriting remains the best solution and automated translators/code generators are not that good. What about still trying to force static typing inside selected parts of SymPy? I mean, once static typing is enforced, it should become easier to translate Python to C++ by hand, because one is not obliged to heavily alter the algorithm in case of variables of ambiguous type. -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. For more options, visit https://groups.google.com/groups/opt_out.
