def mock_qnode(mock_device):
"""Provides a circuit for the subsequent tests of the operation queue"""
def circuit(x):
qml.RX(x, wires=[0])
qml.CNOT(wires=[0, 1])
qml.RY(0.4, wires=[0])
qml.RZ(-0.2, wires=[1])
return qml.expval(qml.PauliX(0)), qml.expval(qml.PauliZ(1))
node = BaseQNode(circuit, mock_device)
node._construct([1.0], {})
return node
def test_print_applied_with_probs(self, mock_device):
"""Test that printing applied gates works correctly when probs are returned"""
H = np.array([[0, 1], [1, 0]])
def circuit(x):
qml.RX(x, wires=[0])
qml.CNOT(wires=[0, 1])
qml.SWAP(wires=[1, 0])
qml.RZ(-0.2, wires=[1])
return qml.probs(wires=[0]), qml.var(qml.Hermitian(H, wires=1))
expected_qnode_print = textwrap.dedent(
"""\
Operations
==========
RX({x}, wires=[0])
CNOT(wires=[0, 1])
SWAP(wires=[1, 0])
RZ(-0.2, wires=[1])
Observables
===========
probs(wires=[0])
var(Hermitian(array([[0, 1],
[1, 0]]), wires=[1]))"""
)
node = BaseQNode(circuit, mock_device)
# test before construction
f = io.StringIO()
with contextlib.redirect_stdout(f):
node.print_applied()
out = f.getvalue().strip()
assert out == "QNode has not yet been executed."
# construct QNode
f = io.StringIO()
node._set_variables([0.1], {})
node._construct([0.1], {})
with contextlib.redirect_stdout(f):
node.print_applied()
out = f.getvalue().strip()
assert out == expected_qnode_print.format(x=0.1)
def test_operation_appending(self, mock_device):
"""Tests that operations are correctly appended."""
CNOT = qml.CNOT(wires=[0, 1])
def circuit(x):
qml.QueuingContext.append_operator(CNOT)
qml.RY(0.4, wires=[0])
qml.RZ(-0.2, wires=[1])
return qml.expval(qml.PauliX(0)), qml.expval(qml.PauliZ(1))
qnode = BaseQNode(circuit, mock_device)
qnode._construct([1.0], {})
assert qnode.ops[0].name == "CNOT"
assert qnode.ops[1].name == "RY"
assert qnode.ops[2].name == "RZ"
assert qnode.ops[3].name == "PauliX"
def test_operation_removal(self, mock_device):
"""Tests that operations are correctly removed."""
def circuit(x):
RX = qml.RX(x, wires=[0])
qml.CNOT(wires=[0, 1])
qml.RY(0.4, wires=[0])
qml.RZ(-0.2, wires=[1])
qml._current_context._remove_op(RX)
return qml.expval(qml.PauliX(0)), qml.expval(qml.PauliZ(1))
qnode = BaseQNode(circuit, mock_device)
qnode._construct([1.0], {})
assert qnode.ops[0].name == "CNOT"
assert qnode.ops[1].name == "RY"
assert qnode.ops[2].name == "RZ"
assert qnode.ops[3].name == "PauliX"
