Indeed it works in Sage 8.4. Thanks! On Wednesday, October 9, 2019 at 8:34:41 AM UTC-7, Dima Pasechnik wrote: > > This got broken in Sage 8.5. > (still works in 8.4) > > > > On Wed, Oct 9, 2019 at 6:09 AM David Joyner <wdjo...@gmail.com > <javascript:>> wrote: > >> >> >> On Wed, Oct 9, 2019 at 1:33 AM Robert Samal <rober...@gmail.com >> <javascript:>> wrote: >> >>> 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) >>> >>> >> Yes. I can confirm it works with "sparse=True" removed *or* if GF(3) is >> replaced by ZZ. >> So there's an easy workaround but maybe the docs or the code has a bug? >> Thanks for reporting. >> >> 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-s...@googlegroups.com <javascript:>. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/sage-support/6ac68e19-7c5a-4be1-ba10-1bac22cddc62%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/sage-support/6ac68e19-7c5a-4be1-ba10-1bac22cddc62%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- >> 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-s...@googlegroups.com <javascript:>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/sage-support/CAEQuuAWQYKhtkVme8wHkJTj38QkmfnSJf3_Lhtqj9PxJmq8HcQ%40mail.gmail.com >> >> <https://groups.google.com/d/msgid/sage-support/CAEQuuAWQYKhtkVme8wHkJTj38QkmfnSJf3_Lhtqj9PxJmq8HcQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> >
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