It works OK in gp: gp: A = [6, 0, -2, 4, 0, 0, 0, -2; 14, -1, 0, 6, 0, -1, -1, 1; 2, 2, 0, 1, 0, 0, 1, 0; -12, 0, 5, -8, 0, 0, 0, 4; 0, 4, 0, 0, 0, 0, 4, 0; 0, 0, 0, 0, 1, 0, 0, 0; -14, 2, 0, -6, 0, 2, 2, -1; -4, 0, 2, -4, 0, 0, 0, 4]
[6 0 -2 4 0 0 0 -2] [14 -1 0 6 0 -1 -1 1] [2 2 0 1 0 0 1 0] [-12 0 5 -8 0 0 0 4] [0 4 0 0 0 0 4 0] [0 0 0 0 1 0 0 0] [-14 2 0 -6 0 2 2 -1] [-4 0 2 -4 0 0 0 4] gp: FB = matfrobenius(A,2) [[0, 0, 0, 4, 0, 0, 0, 0; 1, 0, 0, 4, 0, 0, 0, 0; 0, 1, 0, 1, 0, 0, 0, 0; 0, 0, 1, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 4, 0; 0, 0, 0, 0, 1, 0, 0, 0; 0, 0, 0, 0, 0, 1, 1, 0; 0, 0, 0, 0, 0, 0, 0, 2], [1, -1/2, 1/16, 15/64, 3/128, 7/64, -23/64, 43/128; 0, 0, -5/64, -13/128, -15/256, 17/128, -7/128, 53/256; 0, 0, 9/128, -11/128, -7/128, -1/32, 5/128, 5/32; 0, 0, -5/128, 0, 7/256, -7/128, -1/64, 9/256; 0, 1, 1/16, 5/32, -17/64, -1/32, 31/32, -21/64; 0, 0, 1/32, 5/64, 31/128, -17/64, -1/64, -21/128; 0, 0, 1/32, 5/64, -1/128, 15/64, -1/64, -21/128; 0, 0, 1, 5/2, -1/4, -1/2, -1/2, -21/4]] gp: F=FB[1]; B=FB[2]; gp: B^-1 * F*B == A 1 In your On 18 May 2010 17:07, Clement Pernet <clement.per...@gmail.com> wrote: > Hi there, > > Sage is producing a wrong answer when asked to compute a Frobenius normal > form of a matrix, with the transformation matrix: > > sage: sage: A=matrix(ZZ,8,[[6,0,-2,4,0,0,0,-2],[14,-1,0,6,0,-1,-1,1],\ > [2,2,0,1,0,0,1,0],[-12,0,5,-8,0,0,0,4],[0,4,0,0,0,0,4,0],\ > [0,0,0,0,1,0,0,0],[-14,2,0,-6,0,2,2,-1],[-4,0,2,-4,0,0,0,4]]) > sage: F,K=A.frobenius(2) > sage: ~K*F*K==a > False !!! sage: ~K*F*K==A True so it was just a typo! John > > And the answer should be True. > As Sage directly wraps PARI's frobenius form routine, I guess the bug is > there. > Before I post a ticket, has anyone heard about/met this bug before? Is > someone already working on it? > > Cheers, > > Clément > > -- > To post to this group, send an email to sage-devel@googlegroups.com > To unsubscribe from this group, send an email to > sage-devel+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/sage-devel > URL: http://www.sagemath.org > -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
