def test_error_invalid_transform_callable(self):
"""Test that an error is raised if the transform
is applied to an invalid function"""
with pytest.raises(
ValueError,
match="can only be applied to single tape transform functions"
):
qml.qfunc_transform(5)
def test_unparametrized_transform(self):
"""Test that an unparametrized transform can be applied
to a quantum function"""
def my_transform(tape):
for op in tape.operations + tape.measurements:
if op.name == "CRX":
wires = op.wires
param = op.parameters[0]
qml.RX(param, wires=wires[1])
qml.RY(param / 2, wires=wires[1])
qml.CZ(wires=[wires[1], wires[0]])
else:
op.queue()
my_transform = qml.qfunc_transform(my_transform)
def qfunc(x):
qml.Hadamard(wires=0)
qml.CRX(x, wires=[0, 1])
new_qfunc = my_transform(qfunc)
x = 0.543
ops = qml.transforms.make_tape(new_qfunc)(x).operations
assert len(ops) == 4
assert ops[0].name == "Hadamard"
assert ops[1].name == "RX"
assert ops[1].parameters == [x]
assert ops[2].name == "RY"
assert ops[2].parameters == [x / 2]
assert ops[3].name == "CZ"
def test_error_invalid_qfunc(self):
"""Test that an error is raised if the transform
is applied to an invalid function"""
def identity_transform(tape):
for op in tape.operations + tape.measurements:
op.queue()
my_transform = qml.qfunc_transform(identity_transform)
with pytest.raises(
ValueError,
match="does not appear to be a valid Python function"):
my_transform(5)
def test_parametrized_transform(self):
"""Test that a parametrized transform can be applied
to a quantum function"""
def my_transform(tape, a, b):
for op in tape.operations + tape.measurements:
if op.name == "CRX":
wires = op.wires
param = op.parameters[0]
qml.RX(a, wires=wires[1])
qml.RY(qml.math.sum(b) * param / 2, wires=wires[1])
qml.CZ(wires=[wires[1], wires[0]])
else:
op.queue()
my_transform = qml.qfunc_transform(my_transform)
def qfunc(x):
qml.Hadamard(wires=0)
qml.CRX(x, wires=[0, 1])
a = 0.1
b = np.array([0.2, 0.3])
x = 0.543
new_qfunc = my_transform(a, b)(qfunc)
ops = qml.transforms.make_tape(new_qfunc)(x).operations
assert len(ops) == 4
assert ops[0].name == "Hadamard"
assert ops[1].name == "RX"
assert ops[1].parameters == [a]
assert ops[2].name == "RY"
assert ops[2].parameters == [np.sum(b) * x / 2]
assert ops[3].name == "CZ"
