I am running Sagemath 9.1 on macOS 10.15.17 but I think this issue is more about math.
Consider the following code G = GL(2^8, GF(2^8)) A = G.random_element() B = Matrix(A) %time B.is_invertible() C = Matrix(A) %time C.nrows() == C.ncols() == C.rank() The first timer returns 9s while the second timer returns 2ms. I believe that this is because - is_invertible() computes charpoly and read off the det. This is a detour when the base ring is a field. - rank() uses m4rie, which uses asymptotically fast algorithm for rref. Perhaps we can add one more if-brach in is_invertible() that exploits fast rref? -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/71da074c-81cb-47a9-9068-9fadd2c9ea3an%40googlegroups.com.
