Thilina, On Thu, Jul 18, 2013 at 1:43 PM, Thilina Rathnayake <[email protected]> wrote: > Seems like they haven't implement it anywhere else. I found an algorithm > that > was implemented in MAGMA, but it involves lattice reduction and since I am > almost finished with the descent method, I didn't try to implement that. I > would > try that If I can find some free time or perhaps after completing all the > deliverables of my > project proposal.
But you should be able to check the final results, after you implement the calculation of all solutions. Right? > > And once again, Thank you very much mario. If not for your help, I would > have wasted a > lot of time with this. But sadly, there is still a few problems. The > programme ran infinitely > when an input like (-3 , -4) was given. It should return (None, None, None) > in this case. > I fixed it by adding a if condition to return a None-tuple when both the > inputs are negative. > So now it's okay. I have attached the modified version herewith. > > Also when I gave the input (3, 3), it runs infinitely. I couldn't fix it. > But I found a > workaround to get rid of all of these bugs. I used a slightly modified > version of your first > programme and before I call descent() method in it, I made the two inputs A > and B square > free and did some after-processing to recover the solutions for the original > inputs. > Now it's all fine. Excellent! Great job. > > If not for the case with the input (3, 3) ( same thing happens with (7, 7), > ..) your second > programme produces simpler answers than the first one. However there is a > way to reduce > the magnitude of the answers returned by the descent method so we can use it > with the > current implementation if needed. I plan to give the user the choice to > specify whether > the base solutions should be reduced before using them in the > parametrization to find all the > solutions for the equation. So I think the next step is to implement the retrieval of all the solutions, as described by the book, isn't it? Ondrej > > Thank you and best regards, > Thilina > > > > On Thu, Jul 18, 2013 at 7:10 PM, Ondřej Čertík <[email protected]> > wrote: >> >> Thanks Mario! >> >> I really appreciate your help. That's quite amazing that they had few >> bugs in the algorithm. Do you think they didn't actually implement it >> in any software? >> >> Ondrej >> >> On Thu, Jul 18, 2013 at 5:36 AM, mario <[email protected]> wrote: >> > The attached version works in the mentioned cases; the bug is fixed >> > reducing >> > to the case ``A > 0, B > 0`` >> > >> > >> > On Thursday, July 18, 2013 11:28:22 AM UTC+2, Thilina Rathnayake wrote: >> >> >> >> I should try making input coefficients to be square free. I think the >> >> algorithm in general, >> >> does not work when the coefficients are not square free. >> >> >> >> >> >> >> >> On Thu, Jul 18, 2013 at 2:53 PM, Thilina Rathnayake >> >> <[email protected]> >> >> wrote: >> >>> >> >>> We can add descent(23, 616) to the bug list too. It also return (None, >> >>> None, None) >> >>> but (6, 1, 38) is a solution. By finding more and more test cases >> >>> which >> >>> fail, I think we can >> >>> identify a pattern and then the cause for the bug. >> >>> >> >>> Regards, >> >>> Thilina >> >> >> >> >> > -- >> > 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. >> > 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 [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/sympy. >> 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 [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/sympy. > 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. For more options, visit https://groups.google.com/groups/opt_out.
