Dear Fricas developers, I am playing around benchmarking CAS for the computation of polynomial GCDs with tests similar as those given in this paper: https://arxiv.org/pdf/2304.13418.pdf.
More specifically I am using the following test using `Symbolica <https://symbolica.io/>` Python API: ```python a = Expression.parse('(1 + 3*x1 + 5*x2 + 7*x3 + 9*x4 + 11*x5 + 13*x6 + 15*x7)^7 - 1').to_rational_polynomial() b = Expression.parse('(1 - 3*x1 - 5*x2 - 7*x3 + 9*x4 - 11*x5 - 13*x6 + 15*x7)^7 + 1').to_rational_polynomial() g = Expression.parse('(1 + 3*x1 + 5*x2 + 7*x3 + 9*x4 + 11*x5 + 13*x6 - 15*x7)^7 + 3').to_rational_polynomial() ag = a * g bg = b * g print(g.gcd(bg) - g) ``` Which runs in about 7 seconds on my laptop and prints out the expected 0. Then with `FriCAS`, I am doing: ``` a := (1 + 3*x1 + 5*x2 + 7*x3 + 9*x4 + 11*x5 + 13*x6 + 15*x7)^7 - 1; b := (1 - 3*x1 - 5*x2 - 7*x3 + 9*x4 - 11*x5 - 13*x6 + 15*x7)^7 + 1; g := (1 + 3*x1 + 5*x2 + 7*x3 + 9*x4 + 11*x5 + 13*x6 - 15*x7)^7 + 3; ag := a * g; bg := b * g; gcd(ag, bg) -g ``` which runs in about 25 seconds on my laptop but **does not evaluate to zero* *! My question is thus two-fold: a) Is this non-zero result expected? What is the proper way to get the correct GCD? b) Is my usage of `gcd` above the fastest way to compute polynomial GCDs and therefore a fair comparison with other CAS? Thank you for your help, -- Valentin -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" 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/fricas-devel/CABqv2LHqLGS0zXfM_COXe-q_7aWX3WkeANBMYHgfx-3mBq%3Dnuw%40mail.gmail.com.
