Hi, Just to know, witch version of Theano did you used? I have speed up a little the optimization phase of the compilation and I have a PR that will optimize this more.
Also, Theano cache the compilation of the c code. Where this timming done with a empty theano cache or a filled Theano cache? If you ran the same benchmark multiple time on the same computer, only the first time Theano will compile the c code, the other time it will reuse what is in the cache. thanks Frédéric On Sun, Nov 3, 2013 at 3:22 PM, Ronan Lamy <[email protected]> wrote: > Le 03/11/13 14:19, Jason Moore a écrit : > >> Ronan, >> >> Thanks for looking at the derivation code. We haven't ever really had >> any review of it outside of our mechanical engineer group, so this very >> helpful. >> >> I'll review your PR and look into the second two items. >> >> Why do you think the dictionary representation will be so much faster? > > > Using a dict would make Vector.__eq__ a lot less expensive, and make > canonicalisation (as currently done in Vector.__init__) O(len(args)) instead > of O(len(args)**2). > > However, it seems that the main performance issue is that instantiating > Matrix objects is expensive. Using a dict isn't strictly required to solve > this, but the structure I suggest would allow e.g. dot products of vectors > to be decomposed as combinations of multiplications of components and dot > products of base vectors, which can be optimised or cached separately. There > would be no need for intermediate Matrix objects. > > >> >> On Sat, Nov 2, 2013 at 10:11 PM, Ronan Lamy <[email protected] >> <mailto:[email protected]>> wrote: >> >> Le 01/11/13 11:54, Jason Moore a écrit : >> >> I've been tinkering with code generation for ODE's that >> sympy.physics.mechanics spits out and have some results: >> >> http://www.moorepants.info/__blog/pydy-code-gen.html >> >> <http://www.moorepants.info/blog/pydy-code-gen.html> >> >> Several people have posted topics on this recently. We need to >> build in >> a code generator for solving ODE's into SymPy that would play >> well with >> the codegen and autowrap modules. I think I can use this code I >> wrote as >> a base to start working on that but would need some help >> generalizing it >> beyond our systems. Feedback is welcome. >> >> >> I've only looked at the derivation part, it's an interesting >> real-world(ish) benchmark for expression manipulation. However, it >> incurs a lot of avoidable overhead: >> * Extracting some loop constants out of their loops cuts down the >> run-time by 40%, cf. https://github.com/sympy/__sympy/pull/2570 >> >> <https://github.com/sympy/sympy/pull/2570> >> * The creation of temporary objects by the Vector class takes up >> most of the run-time. >> * The internal representation of Vector objects seems inefficient. I >> think it should be switched to a dict-based representation as a >> linear combination of base vectors (e.g. using {I.x: l0, B.y: -l1} >> for l0 * I.x - l1 * B.y). >> >> >> -- >> 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+unsubscribe@__googlegroups.com >> <mailto:sympy%[email protected]>. >> >> To post to this group, send email to [email protected] >> <mailto:[email protected]>. >> Visit this group at http://groups.google.com/__group/sympy >> <http://groups.google.com/group/sympy>. >> For more options, visit https://groups.google.com/__groups/opt_out >> <https://groups.google.com/groups/opt_out>. >> >> >> >> -- >> 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 [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/sympy. >> For more options, visit https://groups.google.com/groups/opt_out. > > > -- > 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 [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/sympy. > For more options, visit https://groups.google.com/groups/opt_out. -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. For more options, visit https://groups.google.com/groups/opt_out.
