On Thu, May 2, 2013 at 8:09 PM, Dale Lukas Peterson <hazelnu...@gmail.com> wrote: > I am quite swamped and only was briefly able to look at your pull > request but I would advise not using or relying on simplify in tests > if at all possible. For one, it is slow, and it alos gives different > results depending on python versions, and finally, its implementation > could easily change down the road and cause test failures. I would > try expand() instead, this should be safer and faster. If you need > comparisons of more complicated symbolic expressions, another approach > might be to numerically evaluate these expressions for several > distinct sets of numerical values of the symbols and compare those to > the numerical evaluation of the known result for the same numeric > values. This has the downside of having to do floating point > comparisons which can be their own can of worms as well, but for some > stuff I think this would be reasonable approach.
SymPy has a function called test_numerically in sympy.utilities.randtest that can help with this approach. Aaron Meurer > > I will look at your PR a bit more tonight and post my comments there. > > > On Thu, May 2, 2013 at 3:21 AM, Varun Joshi <v9jo...@gmail.com> wrote: >> Hi everyone, >> >> Regarding Pull request #2067, I guess the simplify() command works in >> different ways on different python versions. So my test works on python 2.7 >> but not on the other versions. That's rather strange. >> >> Could someone help me out with this? >> >> Varun Joshi >> >> >> On Thu, May 2, 2013 at 6:16 AM, Varun Joshi <v9jo...@gmail.com> wrote: >>> >>> Hello everyone, >>> >>> My name is Varun Joshi. I'm a Masters student in Mechanical Engineering at >>> the Ohio State University where I work in the Movement Lab >>> (http://www.movement.osu.edu). I've been in touch with the PyDy group on >>> their mailing list and since I will be applying to both groups for GSoC I >>> thought it best to introduce myself here as well. >>> >>> The work in my lab is mostly on the dynamics of human walking. We build >>> simple and complex models and use Matlab's ode and optimization suite to >>> test theories and predict behavior. I learned about SymPy recently and would >>> like to contribute to its code base, especially the sympy.physics.mechanics >>> classes and functions. >>> >>> I am interested specifically in the code generation idea under PyDy, i.e. >>> creating output codes which work directly with numerical ODE solvers, and >>> will definitely be visiting this group more often over the coming months to >>> get some guidance. >>> >>> I recently submitted Pull requests #2033 which has been merged with the >>> sympy master. I also submitted Pull request #2067 which needs some more work >>> by the looks of it. >>> >>> My GSoC application is up at >>> http://www.google-melange.com/gsoc/proposal/review/google/gsoc2013/v9joshi/1 >>> and on my Google site >>> https://sites.google.com/site/v9joshi/gsoc-blog/gsocapplication >>> >>> I'd really appreciate some feedback on it if possible (I know it's very >>> close to the deadline). >>> >>> Thank you, >>> >>> Varun Joshi >>> Graduate Student >>> Department of Mechanical and Aerospace Engineering >>> The Ohio State University >> >> >> -- >> 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?hl=en-US. >> For more options, visit https://groups.google.com/groups/opt_out. >> >> > > > > -- > "People call me a perfectionist, but I'm not. I'm a rightist. I do > something until it's right, and then I move on to the next thing." > -- James Cameron > > -- > 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?hl=en-US. > 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 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?hl=en-US. For more options, visit https://groups.google.com/groups/opt_out.
