def test_fidelity() -> None:
rho0 = qf.random_density(4)
rho1 = qf.random_density(4)
fid = qf.fidelity(rho0, rho1)
assert 0.0 <= fid <= 1.0
rho2 = qf.random_density([3, 2, 1, 0])
fid = qf.fidelity(rho0, rho2)
assert 0.0 <= fid <= 1.0
fid = qf.fidelity(rho0, rho0)
assert np.isclose(fid, 1.0)
ket0 = qf.random_state(3)
ket1 = qf.random_state(3)
fid0 = qf.state_fidelity(ket0, ket1)
rho0 = ket0.asdensity()
rho1 = ket1.asdensity()
fid1 = qf.fidelity(rho0, rho1)
assert np.isclose(fid1, fid0)
fid2 = np.cos(qf.fubini_study_angle(ket0.tensor, ket1.tensor)) ** 2
assert np.isclose(fid2, fid0)
def test_fidelity():
rho0 = qf.random_density(4)
rho1 = qf.random_density(4)
fid = qf.fidelity(rho0, rho1)
print('FID', fid)
assert 0.0 <= fid <= 1.0
rho2 = qf.random_density([3, 2, 1, 0])
fid = qf.fidelity(rho0, rho2)
assert 0.0 <= fid <= 1.0
fid = qf.fidelity(rho0, rho0)
print('FID', fid)
assert fid == ALMOST_ONE
ket0 = qf.random_state(3)
ket1 = qf.random_state(3)
fid0 = qf.state_fidelity(ket0, ket1)
rho0 = ket0.asdensity()
rho1 = ket1.asdensity()
fid1 = qf.fidelity(rho0, rho1)
assert qf.asarray(fid1 - fid0) == ALMOST_ZERO
fid2 = bk.cos(qf.fubini_study_angle(ket0.vec, ket1.vec))**2
assert qf.asarray(fid2 - fid0) == ALMOST_ZERO
def test_parameter_shift_circuits() -> None:
"""Checks that gradients calculated with middle out algorithm
match gradients calculated from parameter shift rule.
"""
graph = nx.grid_graph([2, 2])
layers = 2
params = qf.graph_circuit_params(graph, layers)
circ = qf.graph_circuit(graph, layers, params)
N = circ.qubit_nb
qubits = circ.qubits
ket0 = qf.zero_state(qubits)
ket1 = qf.random_state(qubits)
grads = qf.state_fidelity_gradients(ket0, ket1, circ)
for n in range(N):
r, circ0, circ1 = qf.parameter_shift_circuits(circ, n)
fid0 = qf.state_fidelity(circ0.run(ket0), ket1)
fid1 = qf.state_fidelity(circ1.run(ket0), ket1)
grad = r * (fid1 - fid0)
assert np.isclose(grad, grads[n])
def test_swap_test():
import examples.swaptest as ex
ket0 = qf.zero_state([0])
ket1 = qf.random_state([1])
ket2 = qf.random_state([2])
ket = qf.join_states(ket0, ket1)
ket = qf.join_states(ket, ket2)
fid = qf.state_fidelity(ket1, ket2.relabel([1]))
st_fid = ex.swap_test(ket, 0, 1, 2)
assert qf.asarray(fid) / qf.asarray(st_fid) == ALMOST_ONE
def test_swap_test():
import examples.swaptest as ex
ket0 = qf.zero_state([0])
ket1 = qf.random_state([1])
ket2 = qf.random_state([2])
ket = qf.join_states(ket0, ket1)
ket = qf.join_states(ket, ket2)
fid = qf.state_fidelity(ket1, ket2.on(1))
st_fid = ex.swap_test(ket, 0, 1, 2)
assert np.isclose(fid, st_fid)
def main():
"""CLI"""
print(swap_test.__doc__)
print('Randomly generating two 1-qubit states...')
ket0 = qf.zero_state([0])
ket1 = qf.random_state([1])
ket2 = qf.random_state([2])
ket = qf.join_states(ket0, ket1, ket2)
fid = qf.state_fidelity(ket1, ket2.relabel([1]))
st_fid = swap_test(ket, 0, 1, 2)
print('Fidelity: ', qf.asarray(fid))
print('Fidelity from swap test:', qf.asarray(st_fid))
def main():
"""CLI"""
print(swap_test.__doc__)
print("Randomly generating two 1-qubit states...")
ket0 = qf.zero_state([0])
ket1 = qf.random_state([1])
ket2 = qf.random_state([2])
ket = qf.join_states(ket0, ket1)
ket = qf.join_states(ket, ket2)
fid = qf.state_fidelity(ket1, ket2.on(1))
st_fid = swap_test(ket, 0, 1, 2)
print("Fidelity: ", fid)
print("Fidelity from swap test:", st_fid)