Thank you for these instructive benchmarks! Best wishes,
Eric. Le dimanche 4 septembre 2022 à 07:35:18 UTC+2, roger...@gmail.com a écrit : > Thank you very much Eric! It works perfectly well for my needs. > I've tested the time spent for calculating the Riemann tensor (restarting > the kernel to avoid cache) for three different simplifying methods: the > standard, the simplify, and a function that just returns the expression. It > makes a huge difference. > > For the Kerr-Newman metric, without simplification is ~500x faster > (considering the wall time). > > - default > CPU times: user 5min 6s, sys: 4.16 s, total: 5min 10s > Wall time: 3min > > - simplify > CPU times: user 40.1 s, sys: 359 ms, total: 40.4 s > Wall time: 27.3 s > > - no simplification > CPU times: user 468 ms, sys: 785 µs, total: 468 ms > Wall time: 340 ms > > > For the metric given by > > [-1, 0, 0, 0] > [0, h11(t, r, th, ph), h12(t, r, th, ph), h13(t, r, th, ph)] > [0, h12(t, r, th, ph), h22(t, r, th, ph), h23(t, r, th, ph)] > [0, h13(t, r, th, ph), h23(t, r, th, ph), h33(t, r, th, ph)] > > the results are more even impressive. No simplification is ~4000x faster. > > - default > CPU times: user 40min 26s, sys: 17.9 s, total: 40min 43s > Wall time: 31min 29s > > - simplify > CPU times: user 3min 10s, sys: 978 ms, total: 3min 11s > Wall time: 2min 44s > > - no simplification > CPU times: user 715 ms, sys: 14.2 ms, total: 729 ms > Wall time: 573 ms > > Best wishes, > > Rogerio > > Em sábado, 3 de setembro de 2022 às 12:55:33 UTC-3, egourg...@gmail.com > escreveu: > >> Le vendredi 2 septembre 2022 à 08:09:23 UTC+2, roger...@gmail.com a >> écrit : >> >>> Components of tensors in sagemanifolds are nicely simplified through >>> methods of chart functions. However, for large and complicated expressions, >>> such simplifications are very time consuming. >>> Is it possible to turn off these simplifications? >> >> >> Yes, via the method M.set_simplify_function. It suffices to pass a fast >> function as argument, like simplify. >> For instance: >> >> sage: M = Manifold(4, 'M') >> sage: X.<t,x,y,z> = M.chart() >> sage: M.set_simplify_function(simplify) >> >> NB: the call to M.set_simplify_function must be done after the chart(s) >> have been defined. It can also be done chartwise, via >> X.calculus_method().set_simplify_function(simplify) >> >> See >> >> https://doc.sagemath.org/html/en/reference/manifolds/sage/manifolds/manifold.html#sage.manifolds.manifold.TopologicalManifold.set_simplify_function >> for details. >> >> Best wishes, >> >> Eric. >> > -- 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/af76ad88-21ab-44c8-a710-b4c09e6c4b77n%40googlegroups.com.
