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1. Is the problem over GF2?
2. What is the density? Average number of entries per row, say.
3. Do you know the system is consistent?
4. Is An arbitrary solution acceptable or do you need a random sample of the solution space?
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I should have asked the question this way:
Can we effectively use Wiedemann algorithm to determine the consistency of a large sparse rectangular linear system over GF2,rather than using LU decomposition and finding the actual solution?
Dear Taketo Sano, several problems have been corrected in the current git version.
With your example and the current master I have
A is 5 by 4
[[1, 0, 1, 0 ], [0, 1, 1, 1 ], [0, 0, 0, 0 ], [1, 1, 0, 1 ], [1,
0, 1, 0 ]]
B is [ [1 1 0 0 1 ]]
solve.wiedemann.modular...
...
solve.wiedemann.modular (0.000555038 s)
Solution is [ [1 1 0 0 ]]
CHECK
Regards,
Hello, I am new to LinBox.I am trying to solve a sparse linear system via Wiedemann algorithm.
For our case the matrix A is large (n, m > 10,000) rectangular and necessarily not full-rank.Is there a way to solve Ax = b via Widemann algorithm?
I tried `solve(x, A, b, Method::Blackbox());` for a simple case which actually has a solution,but the library reported `bad preconditioner` while computing the minimal polynomial, and could not get a solution.
A = [1, 0, 1, 0;0, 1, 1, 1;0, 0, 0, 0;1, 1, 0, 1;1, 0, 1, 0]
b = [1; 1; 0; 0; 1]
( x = [1; 1; 0; 0] is one solution )
-- Jean-Guillaume Dumas. ____________________________________________________________________ Jean-Guill...@univ-grenoble-alpes.fr Tél.: +33 457 421 732 Professeur, Université Grenoble Alpes. Fax.: +33 457 421 828 Laboratoire Jean Kuntzmann, Mathématiques Appliquées et Informatique 700 avenue centrale, IMAG - CS 40700, 38058 GRENOBLE cedex 9, FRANCE http://ljk.imag.fr/membres/Jean-Guillaume.Dumas ____________________________________________________________________
-- Jean-Guillaume Dumas. ____________________________________________________________________ Jean-Guil...@univ-grenoble-alpes.fr Tél.: +33 457 421 732 Professeur, Université Grenoble Alpes. Fax.: +33 457 421 828 Laboratoire Jean Kuntzmann, Mathématiques Appliquées et Informatique 700 avenue centrale, IMAG - CS 40700, 38058 GRENOBLE cedex 9, FRANCE http://ljk.imag.fr/membres/Jean-Guillaume.Dumas ____________________________________________________________________
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