blob: cb9c59b607a265216da2fc0ff54c040686a697cf [file] [log] [blame]
 #include struct init { init() { std::cout << "[" << "init" << "]" << std::endl; } }; init init_obj; // [init] #include #include using namespace std; using namespace Eigen; int main() { MatrixXd A(2,2); A << 2, -1, 1, 3; cout << "Here is the input matrix A before decomposition:\n" << A << endl; cout << "[init]" << endl; cout << "[declaration]" << endl; PartialPivLU > lu(A); cout << "Here is the input matrix A after decomposition:\n" << A << endl; cout << "[declaration]" << endl; cout << "[matrixLU]" << endl; cout << "Here is the matrix storing the L and U factors:\n" << lu.matrixLU() << endl; cout << "[matrixLU]" << endl; cout << "[solve]" << endl; MatrixXd A0(2,2); A0 << 2, -1, 1, 3; VectorXd b(2); b << 1, 2; VectorXd x = lu.solve(b); cout << "Residual: " << (A0 * x - b).norm() << endl; cout << "[solve]" << endl; cout << "[modifyA]" << endl; A << 3, 4, -2, 1; x = lu.solve(b); cout << "Residual: " << (A0 * x - b).norm() << endl; cout << "[modifyA]" << endl; cout << "[recompute]" << endl; A0 = A; // save A lu.compute(A); x = lu.solve(b); cout << "Residual: " << (A0 * x - b).norm() << endl; cout << "[recompute]" << endl; cout << "[recompute_bis0]" << endl; MatrixXd A1(2,2); A1 << 5,-2,3,4; lu.compute(A1); cout << "Here is the input matrix A1 after decomposition:\n" << A1 << endl; cout << "[recompute_bis0]" << endl; cout << "[recompute_bis1]" << endl; x = lu.solve(b); cout << "Residual: " << (A1 * x - b).norm() << endl; cout << "[recompute_bis1]" << endl; }