def test_nonexistent_index(self, prog):
"""Acting on a non-existent mode raises an error."""
with prog.context as q:
with pytest.raises(IndexError):
ops.Dgate(0.5) | q[3]
with pytest.raises(program.RegRefError, match="does not exist"):
ops.Dgate(0.5) | 3
def test_deleted_index(self, prog):
"""Test that acting on a deleted mode raises an error"""
with prog.context as q:
ops.Del | q[0]
with pytest.raises(program.RegRefError, match="been deleted"):
ops.Dgate(0.5) | 0
with pytest.raises(program.RegRefError, match="been deleted"):
ops.Dgate(0.5) | q[0]
def test_nonexistent(self):
"""Test that acting on a non-existent mode raises an error"""
eng, q = sf.Engine(2)
with eng:
with pytest.raises(IndexError):
ops.Dgate(0.5) | q[3]
with pytest.raises(engine.RegRefError, match="does not exist"):
ops.Dgate(0.5) | 3
def test_print_commands(self, eng, prog):
"""Program.print and Engine.print_applied return correct strings."""
prog = sf.Program(2)
# store the result of the print command in list res
res = []
# use a print function that simply appends the operation
# name to the results list
print_fn = lambda x: res.append(x.__str__())
# prog should now be empty
prog.print(print_fn)
assert res == []
# define some gates
D = ops.Dgate(0.5)
BS = ops.BSgate(2 * np.pi, np.pi / 2)
R = ops.Rgate(np.pi)
with prog.context as q:
alice, bob = q
D | alice
BS | (alice, bob)
ops.Del | alice
R | bob
charlie, = ops.New(1)
BS | (bob, charlie)
ops.MeasureX | bob
ops.Dgate(bob.par).H | charlie
ops.Del | bob
ops.MeasureX | charlie
res = []
prog.print(print_fn)
expected = [
"Dgate(0.5, 0) | (q[0])",
"BSgate(6.283, 1.571) | (q[0], q[1])",
"Del | (q[0])",
"Rgate(3.142) | (q[1])",
"New(1)",
"BSgate(6.283, 1.571) | (q[1], q[2])",
"MeasureX | (q[1])",
"Dgate(q1, 0).H | (q[2])",
"Del | (q[1])",
"MeasureX | (q[2])",
]
assert res == expected
# NOTE optimization can change gate order
result = eng.run(prog, compile_options={'optimize': False})
res = []
eng.print_applied(print_fn)
assert res == ["Run 0:"] + expected
def test_deleted(self):
"""Test that acting on a deleted mode raises an error"""
eng, q = sf.Engine(2)
with eng:
ops.Del | q[0]
with pytest.raises(engine.RegRefError, match="been deleted"):
ops.Dgate(0.5) | 0
with pytest.raises(engine.RegRefError, match="been deleted"):
ops.Dgate(0.5) | q[0]
def test_print_commands(self, backend):
"""Test print_queue and print_applied returns correct strings."""
eng, q = sf.Engine(2)
# define some gates
D = ops.Dgate(0.5)
BS = ops.BSgate(2 * np.pi, np.pi / 2)
R = ops.Rgate(np.pi)
# get register references
alice, bob = q
with eng:
D | alice
BS | (alice, bob)
ops.Del | alice
R | bob
charlie, = ops.New(1)
BS | (bob, charlie)
ops.MeasureX | bob
ops.Dgate(bob).H | charlie
ops.Del | bob
ops.MeasureX | charlie
res = []
print_fn = lambda x: res.append(x.__str__())
eng.print_queue(print_fn)
expected = [
"Dgate(0.5, 0) | (q[0])",
"BSgate(6.283, 1.571) | (q[0], q[1])",
"Del | (q[0])",
"Rgate(3.142) | (q[1])",
"New(1) ",
"BSgate(6.283, 1.571) | (q[1], q[2])",
"MeasureX | (q[1])",
"Dgate(RR(q[1]), 0).H | (q[2])",
"Del | (q[1])",
"MeasureX | (q[2])",
]
assert res == expected
state = eng.run(backend)
# queue should now be empty
res = []
eng.print_queue(print_fn)
assert res == []
# print_applied should now not be empty
res = []
eng.print_applied(print_fn)
assert res == ["Run 0:"] + expected
def test_GBS_compile_nonconsec_measurefock(self):
"""Tests that GBS compilation fails when Fock measurements are made with an intervening gate."""
prog = sf.Program(2)
with prog.context as q:
ops.Dgate(1.0) | q[0]
ops.MeasureFock() | q[0]
ops.Dgate(-1.0) | q[1]
ops.BSgate(-0.5, 2.0) | q # intervening gate
ops.MeasureFock() | q[1]
with pytest.raises(program.CircuitError, match="The Fock measurements are not consecutive."):
prog.compile('gbs')
def test_print_commands(self, eng, prog):
"""Program.print and Engine.print_applied return correct strings."""
prog = sf.Program(2)
res = []
print_fn = lambda x: res.append(x.__str__())
# prog should now be empty
prog.print(print_fn)
assert res == []
# define some gates
D = ops.Dgate(0.5)
BS = ops.BSgate(2 * np.pi, np.pi / 2)
R = ops.Rgate(np.pi)
with prog.context as q:
alice, bob = q
D | alice
BS | (alice, bob)
ops.Del | alice
R | bob
charlie, = ops.New(1)
BS | (bob, charlie)
ops.MeasureX | bob
ops.Dgate(bob).H | charlie
ops.Del | bob
ops.MeasureX | charlie
res = []
prog.print(print_fn)
expected = [
"Dgate(0.5, 0) | (q[0])",
"BSgate(6.283, 1.571) | (q[0], q[1])",
"Del | (q[0])",
"Rgate(3.142) | (q[1])",
"New(1)",
"BSgate(6.283, 1.571) | (q[1], q[2])",
"MeasureX | (q[1])",
"Dgate(RR(q[1]), 0).H | (q[2])",
"Del | (q[1])",
"MeasureX | (q[2])",
]
assert res == expected
state = eng.run(
prog, compile=False
) # FIXME optimization can change gate order, however this is not a good way of avoiding it
res = []
eng.print_applied(print_fn)
assert res == ["Run 0:"] + expected
def test_regref_transform(self, setup_eng):
"""Test circuit with regref transforms doesn't raise any errors"""
eng, prog = setup_eng(2)
with prog.context as q:
ops.MeasureX | q[0]
ops.Sgate(q[0]) | q[1]
# symbolic hermitian conjugate together with register reference
ops.Dgate(q[0]).H | q[1]
ops.Sgate(ops.RR(q[0], lambda x: x ** 2)) | q[1]
ops.Dgate(ops.RR(q[0], lambda x: -x)).H | q[1]
eng.run(prog)
def test_measured_parameter(self, setup_eng):
"""Test that a circuit with measured parameters executes successfully."""
eng, prog = setup_eng(2)
with prog.context as q:
ops.MeasureX | q[0]
ops.Sgate(q[0].par) | q[1]
# symbolic hermitian conjugate together with register reference
ops.Dgate(q[0].par, 0).H | q[1]
# algebraic transformation
ops.Sgate(q[0].par**2) | q[1]
# algebraic transformation and h.c.
ops.Dgate(q[0].par, np.pi).H | q[1]
eng.run(prog)
def test_invalid_measurement(self, eng, prog):
"""Cannot use a measurement before it exists."""
with prog.context as q:
ops.Dgate(q[0]) | q[1]
with pytest.raises(program.CircuitError,
match="nonexistent measurement result"):
eng.run(prog)
def test_corrupt_index(self, prog):
"""User messes up the RegRef indices."""
with prog.context as q:
q[0].ind = 1
with pytest.raises(program.RegRefError,
match="RegRef state has become inconsistent"):
ops.Dgate(0.5) | q[0]
def test_free_parameters(setup_eng, tol):
"""Programs with free parameters."""
eng, prog = setup_eng(1)
x = prog.params("x") # free parameter
with prog.context as q:
ops.Dgate(x) | q
ops.Sgate(-1.2 * x * pf.sin(x**2 - 0.1)) | q
with pytest.raises(ParameterError, match="Unknown free parameter"):
eng.run(prog, args={"foo": 1.0})
with pytest.raises(ParameterError,
match="unbound parameter with no default value"):
eng.run(prog)
# successful run
eng.run(prog, args={x: 0.0})
assert np.all(eng.backend.is_vacuum(tol))
eng.reset()
# now set a default value for the free parameter
x.default = 0.0
eng.run(prog)
assert np.all(eng.backend.is_vacuum(tol))
eng.reset()
# override the default
x.default = 1.0
eng.run(prog, args={x: 0.0})
assert np.all(eng.backend.is_vacuum(tol))
def test_no_return_state(self, eng, prog):
"""Engine returns None when no state is requested"""
with prog.context as q:
ops.Dgate(0.34) | q[0]
res = eng.run(prog, return_state=False)
assert res is None
def test_extract_arbitrary_unitary_one_mode(self, setup_eng, cutoff, tol):
"""Test that arbitrary unitary extraction works for 1 mode"""
S = ops.Sgate(0.4, -1.2)
D = ops.Dgate(2, 0.9)
K = ops.Kgate(-1.5)
# not a state but it doesn't matter
initial_state = np.random.rand(cutoff) + 1j * np.random.rand(cutoff)
eng_ref, p0 = setup_eng(1)
with p0.context as q:
ops.Ket(initial_state) | q
prog = sf.Program(p0)
with prog.context as q:
S | q
D | q
K | q
U = utils.extract_unitary(prog,
cutoff_dim=cutoff,
backend=eng_ref.backend_name)
if isinstance(U, tf.Tensor):
with tf.Session() as sess:
sess.run(tf.global_variables_initializer())
in_state = tf.constant(initial_state.reshape([-1]),
dtype=tf.complex64)
final_state = sess.run(tf.einsum("ab,b", U, in_state))
else:
final_state = U @ initial_state
expected_state = eng_ref.run([p0, prog]).ket()
assert np.allclose(final_state, expected_state, atol=tol, rtol=0)
def test_apply_history(self, setup_eng, pure):
"""Tests the reapply history argument works correctly with a backend"""
eng, q = setup_eng(2)
a = 0.23
r = 0.1
def inspect():
res = []
print_fn = lambda x: res.append(x.__str__())
eng.print_applied(print_fn)
return res
with eng:
ops.Dgate(a) | q[0]
ops.Sgate(r) | q[1]
state1 = eng.run()
expected = [
"Run 0:",
"Dgate({}, 0) | (q[0])".format(a),
"Sgate({}, 0) | (q[1])".format(r),
]
assert inspect() == expected
# reset backend, but reapply history
eng.backend.reset(pure=pure)
state2 = eng.run(apply_history=True)
assert inspect() == expected
assert state1 == state2
# append more commands to the same backend
with eng:
ops.Rgate(r) | q[0]
state3 = eng.run()
expected = [
"Run 0:",
"Dgate({}, 0) | (q[0])".format(a),
"Sgate({}, 0) | (q[1])".format(r),
"Run 1:",
"Rgate({}) | (q[0])".format(r),
]
assert inspect() == expected
assert not state2 == state3
# reset backend, but reapply history
eng.backend.reset(pure=pure)
state4 = eng.run(apply_history=True)
expected = [
"Run 0:",
"Dgate({}, 0) | (q[0])".format(a),
"Sgate({}, 0) | (q[1])".format(r),
"Rgate({}) | (q[0])".format(r),
]
assert inspect() == expected
assert state3 == state4
def layer(params, q):
"""CV quantum neural network layer acting on ``N`` modes.
Args:
params (list[float]): list of length ``2*(max(1, N-1) + N**2 + n)`` containing
the number of parameters for the layer
q (list[RegRef]): list of Strawberry Fields quantum registers the layer
is to be applied to
"""
N = len(q)
M = int(N * (N - 1)) + max(1, N - 1)
int1 = params[:M]
s = params[M:M + N]
int2 = params[M + N:2 * M + N]
dr = params[2 * M + N:2 * M + 2 * N]
dp = params[2 * M + 2 * N:2 * M + 3 * N]
k = params[2 * M + 3 * N:2 * M + 4 * N]
# begin layer
interferometer(int1, q)
for i in range(N):
ops.Sgate(s[i]) | q[i]
interferometer(int2, q)
for i in range(N):
ops.Dgate(dr[i], dp[i]) | q[i]
ops.Kgate(k[i]) | q[i]
def test_merge_regrefs():
"""Test merging two gates with regref parameters."""
prog = Program(2)
with prog.context as q:
ops.MeasureX | q[0]
D = ops.Dgate(q[0])
F = ops.Dgate(q[0], 0.1)
# gates that are the inverse of each other
merged = D.merge(D.H)
assert merged is None
# gates that have different parameters
with pytest.raises(MergeFailure,
match="Don't know how to merge these gates."):
F.merge(D.H)
def test_coherent(self, a, setup_eng, hbar, tol):
"""Test coherent function matches Gaussian backends"""
eng, prog = setup_eng(1)
with prog.context as q:
ops.Dgate(np.abs(a), np.angle(a)) | q[0]
state = eng.run(prog).state
mu, cov = utils.coherent_state(np.abs(a),
np.angle(a),
basis="gaussian",
hbar=hbar)
if eng.backend_name == "gassian":
mu_exp, cov_exp = state.reduced_gaussian(0)
assert np.allclose(mu, mu_exp, atol=tol, rtol=0)
assert np.allclose(cov, cov_exp, atol=tol, rtol=0)
elif eng.backend_name == "bosonic":
_, mu_exp, cov_exp = state.reduced_bosonic(0)
assert np.allclose(np.expand_dims(mu, axis=0),
mu_exp,
atol=tol,
rtol=0)
assert np.allclose(np.expand_dims(cov, axis=0),
cov_exp,
atol=tol,
rtol=0)
def test_extract_arbitrary_unitary_one_mode(self, setup_eng, cutoff, tol):
"""Test that arbitrary unitary extraction works for 1 mode"""
S = ops.Sgate(0.4, -1.2)
D = ops.Dgate(2, 0.9)
K = ops.Kgate(-1.5)
# not a state but it doesn't matter
initial_state = np.random.rand(cutoff) + 1j * np.random.rand(cutoff)
eng_ref, p0 = setup_eng(1)
with p0.context as q:
ops.Ket(initial_state) | q
prog = sf.Program(p0)
with prog.context as q:
S | q
D | q
K | q
U = utils.extract_unitary(prog,
cutoff_dim=cutoff,
backend=eng_ref.backend_name)
if isinstance(U, tf.Tensor):
U = U.numpy()
final_state = U @ initial_state
expected_state = eng_ref.run([p0, prog]).state.ket()
assert np.allclose(final_state, expected_state, atol=tol, rtol=0)
def test_displaced_squeezed(self, setup_eng, hbar, cutoff, bsize, pure,
tol):
"""Test displaced squeezed function matches Fock backends"""
eng, prog = setup_eng(1)
a = 0.32 + 0.1j
r = 0.112
phi = 0.123
with prog.context as q:
ops.Sgate(r, phi) | q[0]
ops.Dgate(np.abs(a), np.angle(a)) | q[0]
state = eng.run(prog).state
ket = utils.displaced_squeezed_state(np.abs(a),
np.angle(a),
r,
phi,
basis="fock",
fock_dim=cutoff,
hbar=hbar)
if not pure:
expected = state.dm()
ket = np.tile(np.outer(ket, ket.conj()), (bsize, 1, 1))
else:
expected = state.ket()
ket = np.tile(ket, (bsize, 1))
assert np.allclose(expected, ket, atol=tol, rtol=0)
def test_program_subroutine(self, setup_eng, tol):
"""Simple quantum program with a subroutine and references."""
eng, prog = setup_eng(2)
# define some gates
D = ops.Dgate(0.5)
BS = ops.BSgate(0.7 * np.pi, np.pi / 2)
R = ops.Rgate(np.pi / 3)
def subroutine(a, b):
"""Subroutine for the quantum program"""
R | a
BS | (a, b)
R.H | a
# main program
with prog.context as q:
# get register references
alice, bob = q
ops.All(ops.Vacuum()) | (alice, bob)
D | alice
subroutine(alice, bob)
BS | (alice, bob)
subroutine(bob, alice)
state = eng.run(prog).state
# state norm must be invariant
if isinstance(eng.backend, BaseFock):
assert np.allclose(state.trace(), 1, atol=tol, rtol=0)
def test_apply_gate(self):
"""Test successful gate application"""
eng, _ = sf.Engine(2)
with eng:
ops.Dgate(0.5) | 0
assert len(eng.cmd_queue) == 1
def test_invalid(self):
"""cannot referring to a register with a non-integral or RegRef object"""
eng, _ = sf.Engine(2)
with eng:
with pytest.raises(engine.RegRefError,
match="using integers and RegRefs"):
ops.Dgate(0) | 1.2
def test_wrong_engine(self):
"""Test that acting on a mode not belonging to the engine raises error"""
eng, _ = sf.Engine(2)
q_new = engine.RegRef(3)
with eng:
with pytest.raises(engine.RegRefError, match="Unknown RegRef."):
ops.Dgate(0.5) | q_new
def test_checkpoints(self, setup_eng, tol):
"""Test history checkpoints work when creating and deleting modes."""
eng, q = setup_eng(2)
alice, bob = q
# define some gates
D = ops.Dgate(0.5)
BS = ops.BSgate(2 * np.pi, np.pi / 2)
R = ops.Rgate(np.pi)
with eng:
D | alice
BS | (alice, bob)
ops.Del | alice
R | bob
charlie, = ops.New(1)
BS | (bob, charlie)
ops.MeasureX | bob
ops.Del | bob
D.H | charlie
ops.MeasureX | charlie
eng.optimize()
state = eng.run()
# state norm must be invariant
if isinstance(eng.backend, BaseFock):
assert np.allclose(state.trace(), 1, atol=tol, rtol=0)
def check_reg(self, expected_n=None):
"""Compare Engine.register with the mode list returned by the backend.
They should always be in agreement after Engine.run(), Engine.reset_queue()
and Engine.reset().
"""
rr = eng.register
modes = eng.backend.get_modes()
# number of elements
assert len(rr) == len(modes)
if expected_n is not None:
assert len(rr) == expected_n
# check indices match
assert np.all([r.ind for r in rr] == modes)
# activity
assert np.all([r.active for r in rr])
# check that reset() works
check_reg(1)
eng.reset()
new_reg = eng.register
# original number of modes
assert len(new_reg) == len(q)
# the regrefs are reset as well
assert np.all([r.val is None for r in new_reg])
check_reg(2)
def test_wrong_index(self):
"""This should never happen!"""
eng, q = sf.Engine(2)
q[0].ind = 1
with eng:
with pytest.raises(engine.RegRefError,
match="Should never happen!"):
ops.Dgate(0.5) | q[0]
def test_no_return_state(backend):
"""Tests that engine returns None when no state is requested"""
eng, q = sf.Engine(2)
with eng:
ops.Dgate(0.34) | q[0]
res = eng.run(backend, return_state=False)
assert res is None
def test_GBS_compile_no_fock_meas(self):
"""Tests that GBS compilation fails when no fock measurements are made."""
prog = sf.Program(2)
with prog.context as q:
ops.Dgate(1.0) | q[0]
ops.Sgate(-0.5) | q[1]
with pytest.raises(program.CircuitError, match="GBS circuits must contain Fock measurements."):
prog.compile('gbs')
def test_apply_history(self, eng):
"""Tests the reapply history argument"""
a = 0.23
r = 0.1
def inspect():
res = []
print_fn = lambda x: res.append(x.__str__())
eng.print_applied(print_fn)
return res
p1 = sf.Program(2)
with p1.context as q:
ops.Dgate(a) | q[1]
ops.Sgate(r) | q[1]
eng.run(p1)
expected = [
"Run 0:",
"Dgate({}, 0) | (q[1])".format(a),
"Sgate({}, 0) | (q[1])".format(r),
]
assert inspect() == expected
# run the program again
eng.reset()
eng.run(p1)
assert inspect() == expected
# apply more commands to the same backend
p2 = sf.Program(2)
with p2.context as q:
ops.Rgate(r) | q[1]
eng.run(p2)
expected = [
"Run 0:",
"Dgate({}, 0) | (q[1])".format(a),
"Sgate({}, 0) | (q[1])".format(r),
"Run 1:",
"Rgate({}) | (q[1])".format(r),
]
assert inspect() == expected
# reapply history
eng.reset()
eng.run([p1, p2])
#expected = [
# "Run 0:",
# "Dgate({}, 0) | (q[1])".format(a),
# "Sgate({}, 0) | (q[1])".format(r),
# "Rgate({}) | (q[1])".format(r),
#]
assert inspect() == expected
