On Wed, Feb 29, 2012 at 9:28 AM, Vinzenz Bargsten <[email protected]> wrote: > Am 28.02.2012 06:41, schrieb Ondřej Čertík: > >> Hi Vinzenz, >> >> On Mon, Feb 27, 2012 at 4:27 PM, Vinzenz Bargsten<[email protected]> >> wrote: >> [...] >>> >>> Thank you very much. I think I get the point, but I will need some time >>> to >>> implement it. >>> If this is working, I can finally get rid of Mathematica and the complete >>> modeling procedure as well as the required model transformations >>> for a 7-axes robot (Kuka LWR) are carried out by sympy. >> >> That'd be really cool. Yes, the trigonometric simplification is pretty >> hard. >> Besides that, how is SymPy doing otherwise in terms of speed compared >> to Mathematica for your problem? >> >> >> Ondrej > > Hi Ondrej, > > your question is not easy to answer. It depends on the actual task and how > you implement it / the algorithm. The simplification problem is an example: > Using the expand()-replace()-solution is probably slower compared to > Mathematica's Simplify[], but using the monomial-based solution may be > faster. > On average, I would say sympy is at least as fast as Mathematica for my > application.
Well, in general, you should be able to just call simplify() (or trigsimp()), and it should just work. So simplification (especially trig simplification) is one area where we can definitely use improvement. > > The advantages of sympy in my eyes compared to Mathematica are that sympy is > deterministic and you get error messages and the messages point to the > problem. This is the first time I've heard this particular reason for SymPy being better. How is Mathematica non-deterministic? I've never used it, except for WolframAlpha, because, as you noted, it's not free, and I don't own a copy. I suppose the better error messages are a result of Python including the traceback? > Besides the math functions (in many cases superior or unique) Cool. What functions are unique? I only know of one that I'm pretty sure is unique (or at least I couldn't find it in their docs), but it's part of the polys module. I guess maybe the code generation stuff? > it > has many convenient functions (such as the printing functions to generate > c-code of your expressions) and one can use all other python functions. -- > and sympy is free ;) > > Regards, > Vinzenz Aaron Meurer -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
