Thanks for sharing the links, Aaron. Regarding Issue https://github.com/sympy/sympy/issues/10426 ,I opened a PR : https://github.com/sympy/sympy/pull/10482 this PR is able to give solutions in simple form in many cases. When I was trying to solve this issue, I found that solveset converts all the trigonometric equations into exponential form then solve them using solveset_complex . I haven't find any method that solves trig equations using fu module. fu module also need more simplify expression in different terms. It is using this algorithms http://rfdz.ph-noe.ac.at/fileadmin/Mathematik_Uploads/ACDCA/DESTIME2006/DES_contribs/Fu/simplification.pdf <http://rfdz.ph-noe.ac.at/fileadmin/Mathematik_Uploads/ACDCA/DESTIME2006/DES_contribs/Fu/simplification.pdf> that contains simple formulas only.
Right now solveset directly convert any trig expression to it's corresponding exponential form. But if we add fu module in this line : https://github.com/sympy/sympy/pull/10482/files#diff-eec0422923e8f100745c015cd8fdd6cfR540 <https://github.com/sympy/sympy/pull/10482/files#diff-eec0422923e8f100745c015cd8fdd6cfR540> then we get simplified trig equations.Then solve them using solveset_complex , This may increase number of solutions.Isn't it ? Other way can be implement a different algorithms. -- Shekhar Prasad Rajak On Thursday, 4 February 2016 00:51:39 UTC+5:30, Aaron Meurer wrote: > > Another good resource for what's there and what doesn't work yet is > https://github.com/sympy/sympy/blob/master/doc/src/modules/solvers/solveset.rst > . > > Personally, I'd like to see solutions from equations involving > trigonometric expressions improved. Right now you will often get an answer > but it is not as simple as it could be (maybe this is more an issue of > simplifying set expressions). For example, solveset(sin(x), domain=S.Reals) > gives {2⋅n⋅π | n ∊ ℤ} ∪ {2⋅n⋅π + π | n ∊ ℤ} but it would be better if it > gave {n⋅π | n ∊ ℤ}. I suggested a potential way to fix this at > https://github.com/sympy/sympy/pull/9500#discussion_r39220151. Fixing > this by improving simplifying set expressions would be nice because then it > would work even for set expressions that don't come directly from solveset. > > A related use-case I found where solveset fails is solving f(x) = f(x + a) > for a not dependent on x. The ability to solve this in the positive or the > negative would tell you if f(x) is periodic (and its period if it is). This > currently fails even for sin(x) ( > https://github.com/sympy/sympy/issues/10426). > > Aaron Meurer > > On Wed, Feb 3, 2016 at 2:05 PM, Shekhar Prasad Rajak < > [email protected] <javascript:>> wrote: > >> >> Hello, >> my name is Shekhar Prasad Rajak.I want to discuss about Solver and >> Solveset module >> https://github.com/sympy/sympy/wiki/GSoC-2016-Ideas#solvers .I am going >> to apply for GSoc'16, so trying to know >> what sympy community expecting. >> Solveset came to Replace all internal solve() calls >> https://github.com/sympy/sympy/issues/8711 >> So I should focus on Solveset,right? >> I have some questions : >> 1.What are the main problems/issues in Solver and Solveset right now? >> 2.Is Solveset module done?If not,what are the main features, that should >> be added ? >> I have seen Harsh's PR : https://github.com/sympy/sympy/pull/7523 >> It seems, these need some works : >> -functions solvable by LambertW >> -functions that can be recast as polynomials with a change of >> variables this, for example; this can be >> factored out of solve where multiple generators are handled >> -use something like this : >> https://github.com/sympy/sympy/pull/7523#issuecomment-62198981 >> to handle the XFAILed test test_real_imag_splitting1, this will be >> handled in the set module. >> >> 3.This is list of Issues/ Discussions I found. >> >> https://github.com/sympy/sympy/wiki/GSoC-2014-Application-Harsh-Gupta:-Solvers#relevant-issues-discussions-and-references >> >> <https://github.com/sympy/sympy/wiki/GSoC-2014-Application-Harsh-Gupta:-Solvers#relevant-issues-discussions-and-references> >> but I don't know, whether they are solved or not. >> Issues which are still open in github repo, need solutions. >> There are also links of pdf and research papers, I am not sure whether >> they are implemented or not. >> >> 4.Can we use python library multiprocessing,Synchronization for the >> faster execution?one issue was opened for the same,which is closed now.But >> it is always better to take less time. >> >> >> -- >> Shekhar Prasad Rajak >> >> -- >> 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] <javascript:>. >> To post to this group, send email to [email protected] <javascript:> >> . >> Visit this group at https://groups.google.com/group/sympy. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/sympy/33a1b294-4a48-413a-a96f-90899291c1b0%40googlegroups.com >> >> <https://groups.google.com/d/msgid/sympy/33a1b294-4a48-413a-a96f-90899291c1b0%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > > -- 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 https://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/35c19f8c-0bc5-4aba-9b13-35bc16aff761%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
