By the way, another good place to start is trying to fix the "NotImplementedError: Cannot work with non-rational coefficients in this case." error. There is a note about this in prde.py. It's pretty bad that risch_integrate(exp(a*x + b*x), x) works but risch_integrate(exp(a*x)*exp(b*x), x) does not.
Aaron Meurer On Fri, Feb 28, 2014 at 6:25 PM, Aaron Meurer <asmeu...@gmail.com> wrote: > There's a lot of work, even just from Bronstein's book. All the three > major subcases, exponential, logarithmic, and trigonometric, have > algorithms that need to be implemented. Most of them are blocking on > some core algorithms, which is where a lot of the work from last > summer's project went. Another key algorithm that needs to be > implemented is the one described in the paper "Simplification of real > elementary functions" (also by Bronstein). Without this algorithm, we > cannot hook up the integrator to the algorithms written by Chetna. > There will also be work beyond that on getting the right kinds of > substitutions to integrate sine and cosine. They have to be translated > to tan to be integrated, but typically you want to translate the > answer back. There are also issues with making sure you do the right > kind of transformation that doesn't introduce new singularities. > > And even if we implement all of Bronstein's book, there is a lot of > further potential work. Bronstein's book only covers the > transcendental case, but there are also the algebraic and mixed cases. > There are also extensions to make the algorithm work with certain > special functions like the error function (there are papers that > discuss this in the references of Bronstein's book, and I'm sure Raoul > could give you plenty if you are shy on references). > > Aaron Meurer > > On Fri, Feb 28, 2014 at 6:15 PM, Anurag Sharma <anurag...@gmail.com> wrote: >> Hi Aaron and everyone >> Apart from from tying loose ends from previous year's GSOC, what more need >> to be implemented ? >> After a cursory glance over the code of cds.py and corresponding Ch-8 in >> Bronstein, I find all the pseudo codes implemented in cds.py. >> Aaron can you point me to some larger chunk which is not implemented. All >> the previous month I was ploughing through Bronstein. Didnt find enough time >> to go through the code implemented. >> I'd be very happy if you could direct me to the portions which are left so >> that I can think of them and plan on how to implement and discuss my ideas >> with you. >> >> Cheers >> >>> >>> >> -- >> 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. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/sympy/58d33625-4b84-4296-b599-57723e15e862%40googlegroups.com. >> >> 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. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAKgW%3D6%2B-BmVjqf03_8G9w78QY1YNKYUohKOS0tR%3DDQuq-RfyNg%40mail.gmail.com. For more options, visit https://groups.google.com/groups/opt_out.
