public void testElements() {
DenseMatrix A = rand(5, 8);
DenseMatrix B = rand(5, 8);
assertTrue(zeros(5, 8).equals(A.sub(A)));
assertTrue(A.equals(A.add(A).div(2)));
assertTrue(ones(5, 8).equals(A.div(A)));
assertTrue(A.equals(A.mul(A).div(A)));
assertTrue(A.neg().abs().equals(A));
assertTrue(A.neg().add(A).equals(zeros(5, 8)));
}
public void testfullpivhouseholderqrsolve() {
int K = thousandconstant;
DenseMatrix A = rand(K, K / 2);
DenseMatrix B = rand(K, K / 3);
Timer timer = new Timer();
DenseMatrix X = A.fullPivHouseholderQRSolve(B);
timer.printTimeCheckMilliseconds();
DenseMatrix AX = A.mmul(X);
double diff = AX.sub(B).abs().sum().s();
assertTrue(diff < 0.01 * K * K / 3);
}