def test_evaluate(self, x, y, tol):
"""Tests correct evaluation"""
dev = qml.device("default.qubit", wires=2)
def circuit(x, y):
qml.RX(x, wires=[0])
qml.RY(y, wires=[1])
qml.CNOT(wires=[0, 1])
return qml.expval(qml.PauliZ(0) @ qml.PauliX(1))
node = BaseQNode(circuit, dev)
res = node.evaluate([x, y], {})
expected = np.sin(y) * np.cos(x)
assert np.allclose(res, expected, atol=tol, rtol=0)
def test_obs_evaluate(self, x, y, tol):
"""Tests correct evaluation swapping out the observables"""
dev = qml.device("default.qubit", wires=2)
def circuit(x, y):
qml.RX(x, wires=[0])
qml.RY(y, wires=[1])
qml.CNOT(wires=[0, 1])
return qml.expval(qml.PauliZ(0) @ qml.PauliX(1))
node = BaseQNode(circuit, dev)
# test standard evaluation
node = BaseQNode(circuit, dev)
res = node.evaluate([x, y], {})
expected = np.sin(y) * np.cos(x)
assert np.allclose(res, expected, atol=tol, rtol=0)
# hot-swap the observable
res = node.evaluate_obs([qml.PauliZ(0) @ qml.PauliZ(1)], [x, y], {})
expected = np.cos(y)
assert np.allclose(res, expected, atol=tol, rtol=0)