triangular solve - Assertion `it && it.index()==i' failed

lzhang Registered Member Posts 5 Karma 0	triangular solve - Assertion `it && it.index()==i' failed Fri Nov 06, 2015 9:15 pm Hi, I have following program which get the triangular view of a sparse matrix and solve it, but it failed. Code: Select all #include <Eigen/SparseCore> typedef Eigen::SparseMatrix<double, Eigen::RowMajor>  MatrixType; typedef Eigen::VectorXd  VecType; int main() {     VecType x, b;     MatrixType A(1000, 1000);     b = VecType::Random(1000);     A.insert(1, 0) =  0.5;     A.insert(10, 1) = 0.8;     A.insert(1, 10) = 0.8;     x = A.triangularView<Eigen::Lower>().solve(b);     std::cout << x << std::endl;     return 0; } The followings are error messages. Code: Select all a.out: /users/lnz5/loc/include/Eigen/src/SparseCore/TriangularSolver.h:124: static void Eigen::internal::sparse_solve_triangular_selector<Lhs, Rhs, Mode, 1, 0>::run(const Lhs&, Rhs&) [with Lhs = const Eigen::SparseMatrix<double>; Rhs = Eigen::Matrix<double, -1, 1>; int Mode = 1]: Assertion `it && it.index()==i' failed.
lzhang Registered Member Posts 5 Karma 0	Re: triangular solve - Assertion `it && it.index()==i' faile Fri Nov 06, 2015 9:33 pm I found the reason. It seem that the diagonal must be non-zero.
ggael Moderator Posts 3447 Karma 19 OS	Re: triangular solve - Assertion `it && it.index()==i' faile Mon Nov 09, 2015 8:59 pm indeed, otherwise the matrix is structurally non invertible

Bookmarks

Who is online

Registered users: bartoloni, Bing [Bot], Evergrowing, Google [Bot]