Hi Mohit, Ok great, I suspected this was the idea but it was not so clear from the proposal. I think it is a good move forward in creating a better structured ODE solver. It will make it easier to debug and improve individual solvers and gives a good structure to the overall DE solver.
Best regards, Nijso On Friday, 2 April 2021 at 19:42:11 UTC+2 mohitbalw...@gmail.com wrote: > Hi Nijso, > > Thanks for the feedback. > Basic Idea is to implement an independent class for each solver and then > from master ode.py we will just iterate and check if it matches the solver > it will return the solution. Here is the issue link where Oscar suggested > this approach : Link <https://github.com/sympy/sympy/issues/18348>. > For Now each class will have their own get_general_solution() which > returns the solution by that solver. I think after classifying them in > these two major categories, then we can move ahead with merging. > I will try to add more details in the proposal for sure. > > regards, > Mohit > > On Fri, Apr 2, 2021 at 12:04 AM nijso.be...@gmail.com < > nijso.be...@gmail.com> wrote: > >> Hi Mohit, >> >> I looked at your proposal. It is not clear to me what the result of the >> refactoring would be in terms of the algorithmic implementation or the >> benefits to the ODE solver. Is it the idea to have independent classes and >> therefore solvers for each of the ODE solvers and classifiers, that can >> then be called from a master ODE solver class, and that can be called >> independently? >> In any case I wouldn't use regular pattern matching to check if an ODE >> belongs to a certain class, as this almost never works consistently and >> reliably, the preferred approach is to use functional operators like >> differentiation to determine the class (like for exact ODEs). For instance >> the well-known example f(x,y) = exp(x*x + y*y) * (cos(x+y) + cos(x-y)) is >> separable. You can only find this with pattern matching if you follow a >> correct sequence of rewriting of the function using known rules for >> trigonometry, logarithms, etc. Your approach does not detail how to do the >> classifications of all the ODEs besides the mention of 'pattern matching'. >> Your proposal for ode.py to loop over the implemented subsolvers, check >> if it matches the 'pattern' and then solve if it matches makes sense. But >> how much of the get_solution() part is shared by the different subsolvers? >> A number of the current subsolvers are actually the same, like the >> subsolvers based on undetermined coefficients,characteristic or homogeneous >> equations, there could be some merging here. Also, how is the order of the >> calls to the different subsolvers determined? Then finally, there should >> be some further refinement in the classification, like first classifying as >> a scalar ODE, then determine the order, then go through the available >> options for this order (since most methods only work for a specific order >> of the ODE), this is not clear from the how you tackle this. >> >> Just some ideas, all the best, >> Nijso >> >> On Thursday, 1 April 2021 at 16:31:23 UTC+2 mohitbalw...@gmail.com wrote: >> >>> Hello everyone, >>> I wanted to share my GSoC proposal if someone can provide a feedback, it >>> would be really helpful. >>> Here is the Link >>> <https://docs.google.com/document/d/1slfj2CJRgKpmf0zOW93YkxYUDUvutTmkDX6BmsFfmIs/edit?usp=sharing> >>> . >>> >>> regards, >>> Mohit >>> >> -- >> 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+un...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/sympy/bb2579ce-bdfa-46b4-a48f-f52a822b63d3n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/sympy/bb2579ce-bdfa-46b4-a48f-f52a822b63d3n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/sympy/35207604-bdeb-4412-817a-9c697b595eb7n%40googlegroups.com.
