> > Would it be proper to autoconvert matrices over RR to RDF in case of the > default precision, so that the more stable numerical algorithms from RDF > can be used? I had proposed one such change in #13660 ( > http://trac.sagemath.org/13660 ) in case of eigenvalue/eigenvector > computations. >
Well, it should also be fixed for a RealField of higher precision. An easy solution for that is to use PARI, which uses a numerically more stable algorithm (Gaussian elimination, choosing pivots of maximal absolute value; I don't know about proven error bounds). Example: sage: A._pari_().matdet() 16801.7979988279 # same as when doing the computation over QQ Sage's determinant() already uses PARI over Z/nZ for n less than the machine word size; it would be trivial to adapt it to work also over the reals. Peter -- 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 post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/groups/opt_out.
