It should be considered a bug in simplify. It's probably not stuck in an endless loop, but rather just an extremely inefficient algorithm. If you end up canceling it with Control-C open an issue with the traceback so we can see where it got stuck.
Aaron Meurer On Fri, Sep 11, 2015 at 7:23 AM, David Menéndez Hurtado <[email protected]> wrote: > Hi, > > I have a very complicated expression. Running simplify on it takes a long > time (running for 70 h and counting), while other similar or even longer > expressions have been done in a few minutes. Is it possible that it has > entered an endless loop? > > The expression as is is good enough for my purposes, but I wanted to report > a possible bug. > > > > a0, a1, a2, b0, b1, b2, c0, c1, c2 = symbols(vector_components, real=True) > angle, torsion = symbols(input_angles, real=True) > length, prev_length = symbols(input_lengths, real=True, positive=True) > > > c0 + length*((a1 - b1)*(b2 - c2) - (a2 - b2)*(b1 - > c1))*sin(angle)*sin(torsion)/sqrt(((a0 - b0)*(b1 - c1) - (a1 - b1)*(b0 - > c0))**2 + ((a0 - b0)*(b2 - c2) - (a2 - b2)*(b0 - c0))**2 + ((a1 - b1)*(b2 - > c2) - (a2 - b2)*(b1 - c1))**2) + length*(-b0 + c0)*cos(angle)/prev_length + > length*((b1 - c1)*((a0 - b0)*(b1 - c1) - (a1 - b1)*(b0 - c0)) + (b2 - > c2)*((a0 - b0)*(b2 - c2) - (a2 - b2)*(b0 - > c0)))*sin(angle)*cos(torsion)/(prev_length*sqrt(((a0 - b0)*(b1 - c1) - (a1 - > b1)*(b0 - c0))**2 + ((a0 - b0)*(b2 - c2) - (a2 - b2)*(b0 - c0))**2 + ((a1 - > b1)*(b2 - c2) - (a2 - b2)*(b1 - c1))**2)) > > > > Thanks, > > /David. > > > -- > 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. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/5cbdccc8-9a4e-4d6f-b439-57e4185b1e40%40googlegroups.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 http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAKgW%3D6KYjwRhU3HRm1u9kwgn%2BeNh_JLn%3De2Wc23CkUEjBq%2BfJA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
