@Test
public void removeRowFromA() {
int remove = 2;
int m = 5;
int n = 3;
DenseMatrix64F A = RandomMatrices.createRandom(m, n, rand);
// create the modified A
DenseMatrix64F A_e = RandomMatrices.createRandom(m - 1, n, rand);
SubmatrixOps.setSubMatrix(A, A_e, 0, 0, 0, 0, remove, n);
SubmatrixOps.setSubMatrix(A, A_e, remove + 1, 0, remove, 0, m - remove - 1, n);
// Compute the solution to the modified system
DenseMatrix64F X = RandomMatrices.createRandom(n, 2, rand);
DenseMatrix64F Y = new DenseMatrix64F(A_e.numRows, X.numCols);
CommonOps.mult(A_e, X, Y);
// create the solver from the original system then modify it
AdjustableLinearSolver adjSolver = new AdjLinearSolverQr();
adjSolver.setA(A);
adjSolver.removeRowFromA(remove);
// see if it produces the epected results
// solve the system and see if it gets the expected solution
DenseMatrix64F X_found = RandomMatrices.createRandom(X.numRows, X.numCols, rand);
adjSolver.solve(Y, X_found);
// see if they produce the same results
assertTrue(MatrixFeatures.isIdentical(X_found, X, 1e-8));
}
@Test
public void addRowToA() {
int insert = 2;
int m = 5;
int n = 3;
DenseMatrix64F A = RandomMatrices.createRandom(m, n, rand);
double row[] = new double[] {1, 2, 3};
// create the modified A
DenseMatrix64F A_e = RandomMatrices.createRandom(m + 1, n, rand);
SubmatrixOps.setSubMatrix(A, A_e, 0, 0, 0, 0, insert, n);
System.arraycopy(row, 0, A_e.data, insert * n, n);
SubmatrixOps.setSubMatrix(A, A_e, insert, 0, insert + 1, 0, m - insert, n);
// Compute the solution to the modified system
DenseMatrix64F X = RandomMatrices.createRandom(n, 2, rand);
DenseMatrix64F Y = new DenseMatrix64F(A_e.numRows, X.numCols);
CommonOps.mult(A_e, X, Y);
// create the solver from A then add a A. The solver
// should be equivalent to one created from A_e
AdjustableLinearSolver adjSolver = new AdjLinearSolverQr();
assertTrue(adjSolver.setA(A));
adjSolver.addRowToA(row, insert);
// solve the system and see if it gets the expected solution
DenseMatrix64F X_found = RandomMatrices.createRandom(X.numRows, X.numCols, rand);
adjSolver.solve(Y, X_found);
// see if they produce the same results
assertTrue(MatrixFeatures.isIdentical(X_found, X, 1e-8));
}