2014-12-04 7:37 UTC+01:00, Jernej <azi.std...@gmail.com>: > val*bm.transpose() is actually a number but the way Sage handles it is > awkward: > > sage: M = Matrix(RR,[[1],[1]]) > sage: Matrix(RR,[[-1,0]])*M > [-1.00000000000000] > sage: abs(Matrix(RR,[[-1,0]])*M) > -1.00000000000000 # some norm of the matrix??
For this very particular problem, you can reproduce it without any multiplication sage: M = matrix(RR, [[-1]]) sage: abs(M) -1.00000000000000 So the problem is with abs(M). The reason is that abs(M) is calling the method M.__abs__(). The latter one is just a shortcut for the determinant. I really do not understand why and it looks like a bug to me. For comparison, in scipy the same function just return the matrix where each entry is replace with its absolute value. Which is much more natural. I opened a ticket for that: http://trac.sagemath.org/ticket/17443 It should be corrected in the next stable release. Thanks for the report Vincent -- 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 post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
