I don't know if there's an existing option to do this. It seems like it would be useful. You can always lower the eps to make the intervals smaller:
>>> Poly(x**6 + 19/5*x**5 + 131/50*x**4 - x**2 - 19/5*x - 131/50, x, >>> domain='QQ').intervals(eps=0.1) [((-29/10, -26/9), 1), ((-1, -1), 1), ((-10/11, -9/10), 1), ((1, 1), 1)] Aaron Meurer On Tue, May 21, 2024 at 2:51 PM Ani J <anij...@gmail.com> wrote: > > > Oh! I see, but i believe that the intervals overlap on the endpoints, is it > possible to make the intervals completely disjoint?? > For example consider the following program: > > from sympy import Poly > from sympy.abc import x > from sympy import div, QQ > p = Poly(x**6 + 19/5*x**5 + 131/50*x**4 - x**2 - 19/5*x - 131/50, x, > domain='QQ') > p.intervals() > > The intervals that this outputs is: [((-3, -2), 1), ((-1, -1), 1), ((-1, 0), > 1), ((1, 1), 1)] > > Here we can see that the point -1 is a common endpoint between the second and > > the third term. Is it possible to enforce that there be no common point? > > > Best > > On Tuesday, May 21, 2024 at 10:27:15 AM UTC-7 asme...@gmail.com wrote: >> >> Yes, this is the case. The documentation for this method could perhaps >> be improved, but the key word is "isolating", meaning each interval >> contains exactly one root. You can also read more about the algorithm >> that is referenced in the docstring >> https://en.wikipedia.org/wiki/Vincent%27s_theorem >> >> Aaron Meurer >> >> >> On Tue, May 21, 2024 at 9:18 AM Chris Smith <smi...@gmail.com> wrote: >> > >> > I strongly suspect that the roots returned by `Poly.intervals` have only >> > one root in them (by definition). If you use `refine_root(lo,hi,eps)` to >> > refine the root bounds to arbitrary width and give it an interval in which >> > there is more than one root, it will raise an error. >> > >> > /c >> > On Tuesday, May 21, 2024 at 6:06:14 AM UTC-5 ani...@gmail.com wrote: >> >> >> >> Is it possible to use SymPy library to get intervals (with rational >> >> endpoints) such that there is exactly one root in the interval? I would >> >> like to use an implementation of RRI algorithm for my purpose. I believe >> >> that the interval function does this. Is this correct? Is it guaranteed >> >> that the output intervals are guaranteed to not have any common points? >> >> >> >> >> > -- >> > 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/807f8910-040d-475b-91b6-a5002cedeea0n%40googlegroups.com. > > -- > 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/884eb7ff-0762-4771-a81f-930c13dada2dn%40googlegroups.com. -- 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/CAKgW%3D6LCaEVXOcE_Y8%3DuwPD9mxkDmRy-zpDOvFORRP%2BoAZxyxQ%40mail.gmail.com.
