1 int n = 10000; 2 VectorXd x(n), b(n); 3 SparseMatrix<double> A(n,n); 4 /* ... fill A and b ... */ 5 BiCGSTAB<SparseMatrix<double> > solver; 6 solver.compute(A); 7 x = solver.solve(b); 8 std::cout << "#iterations: " << solver.iterations() << std::endl; 9 std::cout << "estimated error: " << solver.error() << std::endl; 10 /* ... update b ... */ 11 x = solver.solve(b); // solve again