def test_qubit_unitary():
"""Test ctrl on QubitUnitary and ControlledQubitUnitary"""
with QuantumTape() as tape:
ctrl(qml.QubitUnitary,
1)(np.array([[1.0, 1.0], [1.0, -1.0]]) / np.sqrt(2.0), wires=0)
tape = expand_tape(
tape, 3, stop_at=lambda op: not isinstance(op, ControlledOperation))
assert_equal_operations(tape.operations, [
qml.ControlledQubitUnitary(
np.array([[1.0, 1.0], [1.0, -1.0]]) / np.sqrt(2.0),
control_wires=1,
wires=0)
])
with QuantumTape() as tape:
ctrl(qml.ControlledQubitUnitary,
1)(np.array([[1.0, 1.0], [1.0, -1.0]]) / np.sqrt(2.0),
control_wires=2,
wires=0)
tape = expand_tape(
tape, 3, stop_at=lambda op: not isinstance(op, ControlledOperation))
assert_equal_operations(tape.operations, [
qml.ControlledQubitUnitary(
np.array([[1.0, 1.0], [1.0, -1.0]]) / np.sqrt(2.0),
control_wires=[1, 2],
wires=0)
])
def test_diagonal_ctrl():
"""Test ctrl on diagonal gates."""
with QuantumTape() as tape:
ctrl(qml.DiagonalQubitUnitary, 1)(np.array([-1.0, 1.0j]), wires=0)
tape = expand_tape(tape, 3, stop_at=lambda op: not isinstance(op, ControlledOperation))
assert_equal_operations(
tape.operations, [qml.DiagonalQubitUnitary(np.array([1.0, 1.0, -1.0, 1.0j]), wires=[1, 0])]
)
def test_multi_control():
"""Test control with a list of wires."""
with QuantumTape() as tape:
CCX = ctrl(qml.PauliX, control=[3, 7])
CCX(wires=0)
assert len(tape.operations) == 1
op = tape.operations[0]
assert isinstance(op, ControlledOperation)
new_tape = expand_tape(tape, 3)
assert_equal_operations(new_tape.operations, [qml.Toffoli(wires=[7, 3, 0])])
def test_nested_control():
"""Test nested use of control"""
with QuantumTape() as tape:
CCX = ctrl(ctrl(qml.PauliX, 7), 3)
CCX(wires=0)
assert len(tape.operations) == 1
op = tape.operations[0]
assert isinstance(op, ControlledOperation)
new_tape = expand_tape(tape, 3)
assert_equal_operations(new_tape.operations, [qml.Toffoli(wires=[7, 3, 0])])
def test_no_control_defined():
"""Test a custom operation with no control transform defined."""
# QFT has no control rule defined.
with QuantumTape() as tape:
ctrl(qml.QFT, 2)(wires=[0, 1])
tape = expand_tape(tape)
assert len(tape.operations) == 12
# Check that all operations are updated to their controlled version.
for op in tape.operations:
assert type(op) in {qml.ControlledPhaseShift, qml.Toffoli, qml.CRX, qml.CSWAP}
def test_no_decomposition_defined():
"""Test that a controlled gate that has no control transform defined,
as well as no decomposition transformed defined, still works correctly"""
with QuantumTape() as tape:
ctrl(qml.CZ, 0)(wires=[1, 2])
tape = expand_tape(tape)
assert len(tape.operations) == 1
assert tape.operations[0].name == "ControlledQubitUnitary"
def test_controlled_template():
"""Test that a controlled template correctly expands
on a device that doesn't support it"""
weights = np.ones([3, 2])
with QuantumTape() as tape:
ctrl(qml.templates.BasicEntanglerLayers, 0)(weights, wires=[1, 2])
tape = expand_tape(tape)
assert len(tape.operations) == 9
assert all(o.name in {"CRX", "Toffoli"} for o in tape.operations)
def test_controlled_template_and_operations():
"""Test that a combination of controlled templates and operations correctly expands
on a device that doesn't support it"""
weights = np.ones([3, 2])
def ansatz(weights, wires):
qml.PauliX(wires=wires[0])
qml.templates.BasicEntanglerLayers(weights, wires=wires)
with QuantumTape() as tape:
ctrl(ansatz, 0)(weights, wires=[1, 2])
tape = expand_tape(tape)
assert len(tape.operations) == 10
assert all(o.name in {"CNOT", "CRX", "Toffoli"} for o in tape.operations)
def test_ctrl_within_ctrl():
"""Test using ctrl on a method that uses ctrl."""
def ansatz(params):
qml.RX(params[0], wires=0)
ctrl(qml.PauliX, control=0)(wires=1)
qml.RX(params[1], wires=0)
controlled_ansatz = ctrl(ansatz, 2)
with QuantumTape() as tape:
controlled_ansatz([0.123, 0.456])
tape = expand_tape(
tape, 2, stop_at=lambda op: not isinstance(op, ControlledOperation))
expected = [
qml.CRX(0.123, wires=[2, 0]),
qml.Toffoli(wires=[0, 2, 1]),
qml.CRX(0.456, wires=[2, 0])
]
assert_equal_operations(tape.operations, expected)
