def test_QR():
A = DenseMatrix(3, 3, [12, -51, 4, 6, 167, -68, -4, 24, -41])
Q, R = A.QR()
assert Q == DenseMatrix(3, 3, [
Rational(6, 7),
Rational(-69, 175),
Rational(-58, 175),
Rational(3, 7),
Rational(158, 175),
Rational(6, 175),
Rational(-2, 7),
Rational(6, 35),
Rational(-33, 35)
])
assert R == DenseMatrix(3, 3, [14, 21, -14, 0, 175, -70, 0, 0, 35])
