I ran into an assertion error when trying to return a sorted list whose key was a certain linear combination of eigenvalues of the Laplacian matrix over graphs on nine vertices. Digging into it a bit, the failure happened when comparing an algebraic real number against the same number that was constructed differently (starting with the graph complement). Digging further, the error happens when finding roots of a certain degree 56 polynomial over AA (all the roots are real) but there is no error doing the same thing over QQbar.
Here is a minimal working example: P.<z> = QQ[] rootlist = (z^8 - 32*z^7 + 425*z^6 - 3044*z^5 + 12789*z^4 - 32090*z^3 + 46672*z^2 - 35734*z + 10917).roots(AA) problem = rootlist[-1][0] - rootlist[0][0] - 9 problem.minpoly().roots(AA) -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/34cfe35b-19ee-429a-bdd7-8e8a61a6a8c9n%40googlegroups.com.
