Hi Juan You can just compute it from the result:
sage: H = random_matrix(GF(2), 15, 20) sage: S = H.echelon_form(transformation=True) sage: full_rank_submatrix = H.matrix_from_columns(S.pivots()) sage: U = full_rank_submatrix.inverse() sage: U*H == S True Note: this only works if m has full row rank (which it should have if your input is a parity check matrix). Otherwise, one has to do slightly more work. Best, Johan Juan Grados writes: > More specifically, I need transform a partity check matrix into a > systematic form, but I need the transform matrix > > 2017-06-10 7:06 GMT-03:00 Juan Grados <juan...@gmail.com>: > >> I need an implementaton to perfom a Gaussian elimination on a matrix with >> entries in GF(2). This implementation should return a transformation matrix >> and the result of the gassual elimination. >> >> 2017-06-10 6:51 GMT-03:00 Simon King <simon.k...@uni-jena.de>: >> >>> Hi Juan, >>> >>> On 2017-06-10, Juan Grados <juan...@gmail.com> wrote: >>> > Thank by I get >>> > >>> > ValueError: too many values to unpack >>> > >>> > I think because my matrix has entries in GF(2). >>> >>> You are right. According to the documentation: >>> * "transformation" -- boolean. Whether to also return the >>> transformation matrix. Some matrix backends do not provide this >>> information, in which case this option is ignored. >>> >>> So, unfortunately, it doesn't give the desired transformation >>> matrix. >>> >>> Depending on your application, it could be that LU decomposition >>> does what you need. >>> >>> Best regards, >>> Simon >>> >>> -- >>> 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 https://groups.google.com/group/sage-support. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> >> >> -- >> --------------------------------------------------------------------- >> MSc. Juan del Carmen Grados Vásquez >> Laboratório Nacional de Computação Científica >> Tel: +55 21 97633 3228 <(21)%2097633-3228> >> (http://www.lncc.br/) >> http://juaninf.blogspot.com >> --------------------------------------------------------------------- >> > > > > -- > --------------------------------------------------------------------- > MSc. Juan del Carmen Grados Vásquez > Laboratório Nacional de Computação Científica > Tel: +55 21 97633 3228 > (http://www.lncc.br/) > http://juaninf.blogspot.com > --------------------------------------------------------------------- -- 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 https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
