On Fri, Feb 26, 2016 at 11:28 AM, Oscar Benjamin <[email protected]> wrote: > On 25 February 2016 at 15:30, Oscar Benjamin <[email protected]> > wrote: >> On 25 February 2016 at 10:44, Yingchi Li <[email protected]> wrote: >>> >>> I have found a bug in factor() and simplify() >>> please look at the image below >>> >>> the correct answer is q2 + 0.1 >> >> Looks like a recent regression since I don't see it with 0.7.1 but I >> do with master: > > I traced this to here: > > In [1]: expr = x*sin(y)**2 + x*cos(y)**2 + 0.1*sin(y)**2 + 0.1*cos(y)**2 > > In [2]: p = Poly(expr, x, cos(y), sin(y), domain='RR') > > In [3]: p > Out[3]: Poly(1.0*x*cos(y)**2 + 1.0*x*sin(y)**2 + 0.1*cos(y)**2 + > 0.1*sin(y)**2, x, cos(y), sin(y), domain='RR') > > In [4]: p.rep > Out[4]: DMP([[[1.0], [], [1.0, 0.0, 0.0]], [[0.1], [], [0.1, 0.0, > 0.0]]], RR, None) > > In [5]: p.rep.factor_list() > Out[5]: > (1.0, > [(DMP([[[0.1], [], [0.1, 0.0, 0.0]]], RR, None), 1), > (DMP([[[1.0]], [[0.1]]], RR, None), 1)]) > > I think the bug is in there somehow but I have no idea what it means. > What is p.rep and how do you interpret it?
It's the internal representation of the polynomial. It's a list of lists of lists of the coefficients (one level deep for each variable of the polynomial). factor_list() has a bug with floating point coefficients, it seems. Can you open an issue, if you haven't already? Aaron Meurer > > -- > Oscar > > -- > 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/CAHVvXxTc6KYEwEBP1GqN5eh-W0JgmsGxLD8DpR1HCAzD29%3DTEw%40mail.gmail.com. > 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/CAKgW%3D6LPGY-oF5QZVYqM6q_pnnEwxWGwLmX8yTUnrkj5%2BtGtKQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
