Can you open an issue in the issue tracker for this https://github.com/sympy/sympy/issues/new. It looks like it is getting stuck trying to compute polynomial gcds. The issue seems to be specific to I. If you instead replace J with a real number, it works. My guess is the fact that it's an algebraic extension causes it to get stuck in some slow polys algorithm, or possibly an algorithm that is bugged.
Aaron Meurer On Tue, Oct 11, 2022 at 4:41 AM [email protected] <[email protected]> wrote: > > Consider : > > from sympy import symbols, Eq, solve, I > L1, L2, L3, L4, C1, C2, C3, C4, M23, I1, I2, I3, I4, U, w, p, RL, J = \ > symbols("L1, L2, L3, L4, C1, C2, C3, C4, M23, I1, I2, I3, I4, U, w, p, RL, J") > Sys = [Eq(I1*(J*L1*w - J/(C1*w)) + I2*J/(C1*w), U), > Eq(I2*(J*L2*w - J/(C2*w) - J/(C1*w)) + I3*(J*M23*w + J/(C2*w)) + > I1*J/(C1*w), 0), > Eq(I2*(J*M23*w + J/(C2*w)) + I3*(J*L3*w - J/(C3*w) - J/(C2*w)) + > I4*J/(C3*w), 0), > Eq(I4*RL + I3*J/(C3*w) - I4*J/(C3*w), 0)] > IVars = [I1, I2, I3, I4] > Sol = solve(Sys, IVars) > Chk = [u.subs(Sol).simplify() for u in Sys] > > This system is solved in a matter of milliseconds, and the (unique) solution > is correct : > > >>> Chk [True, True, True, True] > > However, this : > > >>> Sys0 = [u.subs({J:I}) for u in Sys] > >>> Sol0 = solve(Sys0, IVars) > > “never” returns (i. e. didn’t return after >90 minutes). > > WTF ? > > -- > 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 view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/fb2649d3-cba4-4919-bd05-d9de178bb561n%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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAKgW%3D6%2BYf92TG%3DBWjzBK9OVnB4bOt2Qf91vWKA1vgxGdHkj-dg%40mail.gmail.com.
