def test_pre_measure_eng(self, tol):
"""Test that the pre_measure method operates as expected by initializing the engine
correctly"""
dev = qml.device("strawberryfields.gbs", wires=4, cutoff_dim=3)
prog = Program(4)
op1 = GraphEmbed(0.1767767 * np.ones((4, 4)), mean_photon_per_mode=0.25)
prog.append(op1, prog.register)
dev.prog = prog
dev.pre_measure()
assert dev.eng.backend_name == "gaussian"
assert dev.eng.backend_options == {"cutoff_dim": 3}
def test_pre_measure_state_and_samples(self, tol):
"""Test that the pre_measure method operates as expected in analytic mode by generating the
correct output state and not generating samples"""
dev = qml.device("strawberryfields.gbs", wires=4, cutoff_dim=3)
prog = Program(4)
op1 = GraphEmbed(0.1767767 * np.ones((4, 4)), mean_photon_per_mode=0.25)
prog.append(op1, prog.register)
dev.prog = prog
dev.pre_measure()
assert np.allclose(dev.state.displacement(), np.zeros(4))
assert np.allclose(dev.state.cov(), target_cov, atol=tol)
assert dev.samples.size == 0
def test_pre_measure_state_and_samples_non_analytic(self, tol):
"""Test that the pre_measure method operates as expected in non-analytic mode by
generating the correct output state and samples of the right shape"""
dev = qml.device("strawberryfields.gbs", wires=4, cutoff_dim=3, analytic=False, shots=2)
prog = Program(4)
op1 = GraphEmbed(0.1767767 * np.ones((4, 4)), mean_photon_per_mode=0.25)
op2 = MeasureFock()
prog.append(op1, prog.register)
prog.append(op2, prog.register)
dev.prog = prog
dev.pre_measure()
assert np.allclose(dev.state.displacement(), np.zeros(4))
assert np.allclose(dev.state.cov(), target_cov, atol=tol)
assert dev.samples.shape == (2, 4)
