Sorry, F=GF(3), I made my original example shorter and didn't read it properly.
So the full problematic code is B=matrix(GF(3), 2,2,[1,0,1,0], sparse=True) v=vector(GF(3), [1,1]) B.solve_right(v) Thanks, Robert On Tuesday, October 8, 2019 at 5:17:59 PM UTC-7, Robert Samal wrote: > > I am trying to solve a rather large linear systems of equations of GF(3). > As the matrices are sparse, I thought that adding "sparse=True" to the > constructor of the matrix could be of help. However, I ran to a strange > error message. > > B=matrix(GF(3), 2,2,[1,0,1,0], sparse=True) > v=vector(F, [1,1]) > B.solve_right(v) > > The above code yields the following > > TypeError: Cannot convert sage.matrix.matrix_modn_sparse.Matrix_modn_sparse > to sage.matrix.matrix_integer_sparse.Matrix_integer_sparse > > > I am hesitant to paste the whole error message here, but it ends with > reference to file > SageMath/local/lib/python2.7/site-packages/sage/matrix/matrix_modn_sparse.pyx > in > sage.matrix.matrix_modn_sparse.Matrix_modn_sparse._solve_matrix_linbox > (build/cythonized/sage/matrix/matrix_modn_sparse.cpp:11633). > > I am using Sage 8.9, but the same issue was on 8.7 as well. > > Few other observations: > -- works as expected for dense matrices -- or for sparse ones over integers > -- the same issue occurs whether y is a vector or a matrix > -- It behaves the same for systems with no solution. > > Is there some hidden limitation of sparse matrices over finite fields? > I.e., is it a bug or feature? :-) > I tried to RTFM, but couldn't find this discussed. The page for sparse > matrices over > finite fields does not exactly promise the solve method, but it does not > mention it > would not work either. Is it possible to achieve what I want by other means > (in Sage). > > Thanks. > > > > > -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/6ac68e19-7c5a-4be1-ba10-1bac22cddc62%40googlegroups.com.
