def test_init():
p = cirq.RandomGateChannel(sub_gate=cirq.X, probability=0.5)
assert p.sub_gate is cirq.X
assert p.probability == 0.5
with pytest.raises(ValueError, match='probability'):
_ = cirq.RandomGateChannel(sub_gate=cirq.X, probability=2)
with pytest.raises(ValueError, match='probability'):
_ = cirq.RandomGateChannel(sub_gate=cirq.X, probability=-1)
def test_consistent_protocols():
cirq.testing.assert_implements_consistent_protocols(
cirq.RandomGateChannel(sub_gate=cirq.X, probability=1))
cirq.testing.assert_implements_consistent_protocols(
cirq.RandomGateChannel(sub_gate=cirq.X, probability=0))
cirq.testing.assert_implements_consistent_protocols(
cirq.RandomGateChannel(sub_gate=cirq.X,
probability=sympy.Symbol('x') / 2))
cirq.testing.assert_implements_consistent_protocols(
cirq.RandomGateChannel(sub_gate=cirq.X, probability=0.5))
def test_eq():
eq = cirq.testing.EqualsTester()
q = cirq.LineQubit(0)
eq.add_equality_group(
cirq.RandomGateChannel(sub_gate=cirq.X, probability=0.5),
cirq.X.with_probability(0.5))
# Each field matters for equality.
eq.add_equality_group(cirq.Y.with_probability(0.5))
eq.add_equality_group(cirq.X.with_probability(0.25))
# `with_probability(1)` doesn't wrap
eq.add_equality_group(cirq.X, cirq.X.with_probability(1))
eq.add_equality_group(
cirq.X.with_probability(1).on(q),
cirq.X.on(q).with_probability(1),
cirq.X(q),
)
# `with_probability` with `on`.
eq.add_equality_group(
cirq.X.with_probability(0.5).on(q),
cirq.X.on(q).with_probability(0.5),
)
# Flattening.
eq.add_equality_group(
cirq.RandomGateChannel(sub_gate=cirq.Z, probability=0.25),
cirq.RandomGateChannel(sub_gate=cirq.RandomGateChannel(
sub_gate=cirq.Z, probability=0.5),
probability=0.5),
cirq.Z.with_probability(0.5).with_probability(0.5),
cirq.Z.with_probability(0.25),
)
# Supports approximate equality.
assert cirq.approx_eq(
cirq.X.with_probability(0.5),
cirq.X.with_probability(0.50001),
atol=1e-2,
)
assert not cirq.approx_eq(
cirq.X.with_probability(0.5),
cirq.X.with_probability(0.50001),
atol=1e-8,
)
def test_setters_deprecated():
gate = cirq.RandomGateChannel(sub_gate=cirq.X, probability=0.1)
with cirq.testing.assert_deprecated('mutators', deadline='v0.15'):
gate.sub_gate = cirq.Y
assert gate.sub_gate == cirq.Y
with cirq.testing.assert_deprecated('mutators', deadline='v0.15'):
gate.probability = 0.2
assert gate.probability == 0.2
def test_consistent_protocols():
cirq.testing.assert_implements_consistent_protocols(
cirq.RandomGateChannel(sub_gate=cirq.X, probability=1),
ignore_decompose_to_default_gateset=True,
)
cirq.testing.assert_implements_consistent_protocols(
cirq.RandomGateChannel(sub_gate=cirq.X, probability=0),
ignore_decompose_to_default_gateset=True,
)
cirq.testing.assert_implements_consistent_protocols(
cirq.RandomGateChannel(sub_gate=cirq.X,
probability=sympy.Symbol('x') / 2),
ignore_decompose_to_default_gateset=True,
)
cirq.testing.assert_implements_consistent_protocols(
cirq.RandomGateChannel(sub_gate=cirq.X, probability=0.5),
ignore_decompose_to_default_gateset=True,
)
def test_parameterizable(resolve_fn):
a = sympy.Symbol('a')
cy = cirq.ControlledGate(cirq.Y)
cya = cirq.ControlledGate(cirq.YPowGate(exponent=a))
assert cirq.is_parameterized(cya)
assert not cirq.is_parameterized(cy)
assert resolve_fn(cya, cirq.ParamResolver({'a': 1})) == cy
cchan = cirq.ControlledGate(
cirq.RandomGateChannel(sub_gate=cirq.PhaseDampingChannel(0.1),
probability=a))
with pytest.raises(ValueError, match='Cannot control channel'):
resolve_fn(cchan, cirq.ParamResolver({'a': 0.1}))
def test_parameterizable(resolve_fn):
a = sympy.Symbol('a')
qubits = cirq.LineQubit.range(3)
cz = cirq.ControlledOperation(qubits[:1], cirq.Z(qubits[1]))
cza = cirq.ControlledOperation(qubits[:1], cirq.ZPowGate(exponent=a)(qubits[1]))
assert cirq.is_parameterized(cza)
assert not cirq.is_parameterized(cz)
assert resolve_fn(cza, cirq.ParamResolver({'a': 1})) == cz
cchan = cirq.ControlledOperation(
[qubits[0]],
cirq.RandomGateChannel(sub_gate=cirq.PhaseDampingChannel(0.1), probability=a)(qubits[1]),
)
with pytest.raises(ValueError, match='Cannot control channel'):
resolve_fn(cchan, cirq.ParamResolver({'a': 0.1}))
