On 2014-07-16, Juan Grados <juan...@gmail.com> wrote: > Dears members, > > I trying to solve the next problem. Let be the chain of subspaces > J1 \subset J2 \subset J3 \subset J4 over the finite field GF(3), where > dim(J1) = 2, dim(J2) = 4, dim(J3) = 6 and dim(J4)=8. I want extract the > basis vector of the subspace J4-J3, J3-J2 and J2-J1. For J4-J3 I get using > the next code > > K.<t> = GF(3) > J3vectors >= >[[1,0,0,0,0,1,0,1],[0,1,0,0,0,1,0,0],[0,0,1,0,0,2,0,2],[0,0,0,1,0,0,0,2],[0,0,0,0,1,1,0,1],[0,0,0,0,0,0,1,1]] > J3 = span(K,J3vectors) > transpose(J3.basis_matrix()).kernel() > > But I don't know How I will be able to obtain J3-J2 and J2-J1, with J3, J2 .
well, you'd rather work with the quotient spaces and the corresponding maps: E.g. your J4/J3 you can get as sage: (K^8/J3).quotient_map() Vector space morphism represented by the matrix: [1 0] [0 1] [2 0] [2 1] [1 0] [0 2] [1 2] [2 1] In the same vein you can get (J3/J2).quotient_map(). (then your morphism will be given as a matrix in the basis of J3). Etc. -- 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.
