I was using sage 4.4.2.alpha0. There was a pari upgrade recently; but I don't know if it affected that function.
John On 18 May 2010 17:33, Clement Pernet <clement.per...@gmail.com> wrote: > Hmmm, sorry for the typo, but I still have the bug by replacing a with A (I > had a copy of A in a). > > Now, I realized that I'm using the 4.3.3 version. And it actually works on > the lastest version (on sagenb.org) > So I assume the bug has been fixed in gp recently, or something. > > Problem fixed! > Sorry for the noise. > > Clément > > John Cremona a écrit : >> >> 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 > -- 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
