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.
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 <[email protected]> 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 <[email protected]> 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 [email protected]. > To post to this group, send email to [email protected]. > 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy?hl=en-US. For more options, visit https://groups.google.com/groups/opt_out.
