def test_input_gates_not_of_correct_form(self):
"""Test that an error is thrown if gates marked as encoding gates
are not single-parameter gates."""
dev = qml.device("default.qubit", wires=3)
@qml.qnode(dev)
def circuit():
qml.RX(0.1, wires=0, id="x")
qml.Rot(0.2, 0.3, 0.4, wires=1, id="x")
return qml.expval(qml.PauliZ(wires=0))
with pytest.raises(ValueError, match="Can only consider one-parameter gates"):
spectrum(circuit)()
def test_spectrum_changes_with_qnode_args(self):
"""Test that the spectrum changes per call if a qnode argument changes the
circuit architecture."""
dev = qml.device("default.qubit", wires=3)
@qml.qnode(dev)
def circuit(last_gate):
qml.RX(0.1, wires=0, id="x")
qml.RX(0.2, wires=1, id="x")
if last_gate:
qml.RX(0.3, wires=2, id="x")
return qml.expval(qml.PauliZ(wires=0))
res_true = spectrum(circuit)(True)
assert np.allclose(res_true["x"], range(-3, 4))
res_false = spectrum(circuit)(False)
assert np.allclose(res_false["x"], range(-2, 3))
def test_encoding_gates(self):
"""Test that the spectrum contains the ids provided in encoding_gates, or
all ids if encoding_gates is None."""
dev = qml.device("default.qubit", wires=1)
@qml.qnode(dev)
def circuit(x):
qml.RX(x, wires=0, id="x")
qml.RY(0.4, wires=0, id="other")
return qml.expval(qml.PauliZ(wires=0))
res = spectrum(circuit, encoding_gates=["x"])(0.1)
assert res == {"x": [-1.0, 0.0, 1.0]}
res = spectrum(circuit, encoding_gates=["x", "other"])(0.1)
assert res == {"x": [-1.0, 0.0, 1.0], "other": [-1.0, 0.0, 1.0]}
res = spectrum(circuit)(0.1)
assert res == {"x": [-1.0, 0.0, 1.0], "other": [-1.0, 0.0, 1.0]}
res = spectrum(circuit, encoding_gates=["a"])(0.1)
assert res == {"a": []}
def test_integration_autograd(self):
"""Test that the spectra of a circuit is calculated correctly
in the autograd interface."""
x = pnp.array([1.0, 2.0, 3.0], requires_grad=False)
w = pnp.array([[-1, -2, -3], [-4, -5, -6]], requires_grad=True)
dev = qml.device("default.qubit", wires=3)
qnode = qml.QNode(circuit, dev, interface="autograd")
res = spectrum(qnode)(x, w)
for (k1, v1), (k2, v2) in zip(res.items(), expected_result.items()):
assert k1 == k2
assert v1 == v2
def test_integration_tf(self):
"""Test that the spectra of a circuit is calculated correctly
in the tf interface."""
tf = pytest.importorskip("tensorflow")
dev = qml.device("default.qubit", wires=3)
qnode = qml.QNode(circuit, dev, interface="tf")
x = tf.Variable([1.0, 2.0, 3.0])
w = tf.constant([[-1, -2, -3], [-4, -5, -6]])
res = spectrum(qnode)(x, w)
assert res
for (k1, v1), (k2, v2) in zip(res.items(), expected_result.items()):
assert k1 == k2
assert v1 == v2
def test_integration_torch(self):
"""Test that the spectra of a circuit is calculated correctly
in the torch interface."""
torch = pytest.importorskip("torch")
x = torch.tensor([1.0, 2.0, 3.0], requires_grad=True)
w = torch.tensor([[-1, -2, -3], [-4, -5, -6]], requires_grad=False)
dev = qml.device("default.qubit", wires=3)
qnode = qml.QNode(circuit, dev, interface="torch")
res = spectrum(qnode)(x, w)
assert res
for (k1, v1), (k2, v2) in zip(res.items(), expected_result.items()):
assert k1 == k2
assert v1 == v2
def test_spectrum_grows_with_gates(self, n_layers, n_qubits):
"""Test that the spectrum grows linearly with the number of
encoding gates if we use Pauli rotation encoding."""
dev = qml.device("default.qubit", wires=n_qubits)
@qml.qnode(dev)
def circuit(x):
for l in range(n_layers):
for i in range(n_qubits):
qml.RX(x, wires=i, id="x")
qml.RY(0.4, wires=i)
return qml.expval(qml.PauliZ(wires=0))
res = spectrum(circuit)(0.1)
expected_degree = n_qubits * n_layers
assert np.allclose(res["x"], range(-expected_degree, expected_degree + 1))
def test_integration_jax(self):
"""Test that the spectra of a circuit is calculated correctly
in the jax interface."""
jax = pytest.importorskip("jax")
from jax import numpy as jnp
x = jnp.array([1.0, 2.0, 3.0])
w = [[-1, -2, -3], [-4, -5, -6]]
dev = qml.device("default.qubit", wires=3)
qnode = qml.QNode(circuit, dev, interface="jax")
res = spectrum(qnode)(x, w)
assert res
for (k1, v1), (k2, v2) in zip(res.items(), expected_result.items()):
assert k1 == k2
assert v1 == v2