Merge branch 'main' into mhucka-add-recommended-files

.github/workflows/stale.yml

@@ -1,19 +1,57 @@
-name: "Mark and close stale issues"
+# Summary: perform stale issue & PR handling on a schedule
+# For more info, see https://github.com/actions/stale/
+
+name: "Label and close stale issues & PRs"
+
 on:
   schedule:
   - cron: "0 0 * * *"
+  workflow_dispatch:
+    inputs:
+      debug:
+        # Note: the job body sets `debug-only` to false by default. The value
+        # of inputs.debug is an empty string unless this workflow is invoked
+        # manually. When it's invoked manually, GitHub's GUI presents the user
+        # with a checkbox for this flag; we default that checkbox to true
+        # because the most likely reason for a manual run is debugging.
+        description: "Run in debug mode (dry run)"
+        type: boolean
+        default: true
 
 jobs:
   stale:
+    name: Label and/or close stale issues and PRs
     runs-on: ubuntu-20.04
     steps:
     - uses: actions/stale@v9
       with:
-        repo-token: ${{ secrets.GITHUB_TOKEN }}
-        stale-issue-message: 'This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 30 days'
-        days-before-stale: 30
-        days-before-close: 30
-        close-issue-message: 'Issue closed due to inactivity.'
+        repo-token: ${{secrets.GITHUB_TOKEN}}
+        debug-only: ${{inputs.debug || false}}
+        days-before-stale: 90
+        days-before-close: 60
         stale-issue-label: 'status/stale'
         stale-pr-label: 'status/stale'
         exempt-issue-labels: 'triage/accepted,triage/discuss,kind/design-issue,kind/health,kind/roadmap-item,kind/task'
+        stale-issue-message: >
+          This issue has been automatically labeled as stale because 90 days
+          have passed without comments or other activity. If no further
+          activity occurs and the `status/stale` label is not removed within
+          60 days, it will be closed. If you believe this is in error or would
+          like to discuss it further, please leave a comment here.
+        stale-pr-message: >
+          This pull request has been automatically labeled as stale because 90
+          days have passed without comments or other activity. If no further
+          activity occurs and the `status/stale` label is not removed within 60
+          days, it will be closed. If you believe this is in error or would
+          like to discuss it further, please leave a comment here.
+        close-issue-message: >
+          This issue has been closed due to inactivity for 60 days since the
+          time the stale label was applied. If you believe this is in error or
+          would like to discuss it further, please either open a new issue
+          (and reference this one in it, for continuity) or reach out to the
+          Cirq project maintainers at [email protected].
+        close-pr-message: >
+          This pull-request has been closed due to inactivity for 60 days
+          since the time the stale label was applied. If you believe this is
+          in error or would like to discuss it further, please reach out to
+          the Cirq project maintainers at [email protected].

cirq-core/cirq/experiments/xeb_fitting.py

@@ -654,6 +654,7 @@ def _fit_exponential_decay(
             fidelities,
             p0=(a_0, layer_fid_0),
             bounds=((0, 0), (1, 1)),
+            maxfev=1000,
         )
     except ValueError:  # pragma: no cover
         return 0, 0, np.inf, np.inf

cirq-core/cirq/experiments/z_phase_calibration_test.py

@@ -27,10 +27,12 @@
 from cirq.experiments.xeb_fitting import XEBPhasedFSimCharacterizationOptions
 
 _ANGLES = ['theta', 'phi', 'chi', 'zeta', 'gamma']
+# fix random generator seed to ensure reproducibility and faster convergence
+_SEED = 276154030
 
 
-def _create_tests(n, seed, with_options: bool = False):
-    rng = np.random.default_rng(seed)
+def _create_tests(n, with_options: bool = False):
+    rng = np.random.default_rng(_SEED)
     angles = (rng.random((n, 5)) * 2 - 1) * np.pi
     # Add errors to the last 3 angles (chi, zeta, gamma).
     # The errors are in the union (-2, -1) U (1, 2).
@@ -86,8 +88,7 @@ def _core_iterator(
 
 
 @pytest.mark.parametrize(
-    ['angles', 'error', 'characterization_flags'],
-    _create_tests(n=10, seed=32432432, with_options=True),
+    ['angles', 'error', 'characterization_flags'], _create_tests(n=10, with_options=True)
 )
 def test_calibrate_z_phases(angles, error, characterization_flags):
 
@@ -98,7 +99,7 @@ def test_calibrate_z_phases(angles, error, characterization_flags):
         **{f'{n}_default': t for n, t in zip(_ANGLES, angles)}, **characterization_flags
     )
 
-    sampler = _TestSimulator(original_gate, actual_gate, seed=0)
+    sampler = _TestSimulator(original_gate, actual_gate, seed=_SEED)
     qubits = cirq.q(0, 0), cirq.q(0, 1)
     calibrated_gate = calibrate_z_phases(
         sampler,
@@ -109,6 +110,7 @@ def test_calibrate_z_phases(angles, error, characterization_flags):
         n_combinations=10,
         n_circuits=10,
         cycle_depths=range(3, 10),
+        random_state=_SEED,
     )[qubits]
 
     initial_unitary = cirq.unitary(original_gate)
@@ -126,13 +128,13 @@ def test_calibrate_z_phases(angles, error, characterization_flags):
     assert new_dist < original_dist or new_dist < 1e-6
 
 
-@pytest.mark.parametrize(['angles', 'error'], _create_tests(n=3, seed=32432432))
+@pytest.mark.parametrize(['angles', 'error'], _create_tests(n=3))
 def test_calibrate_z_phases_no_options(angles, error):
 
     original_gate = cirq.PhasedFSimGate(**{k: v for k, v in zip(_ANGLES, angles)})
     actual_gate = cirq.PhasedFSimGate(**{k: v + e for k, v, e in zip(_ANGLES, angles, error)})
 
-    sampler = _TestSimulator(original_gate, actual_gate, seed=0)
+    sampler = _TestSimulator(original_gate, actual_gate, seed=_SEED)
     qubits = cirq.q(0, 0), cirq.q(0, 1)
     calibrated_gate = calibrate_z_phases(
         sampler,
@@ -143,6 +145,7 @@ def test_calibrate_z_phases_no_options(angles, error):
         n_combinations=10,
         n_circuits=10,
         cycle_depths=range(3, 10),
+        random_state=_SEED,
     )[qubits]
 
     initial_unitary = cirq.unitary(original_gate)
@@ -160,13 +163,13 @@ def test_calibrate_z_phases_no_options(angles, error):
     assert new_dist < original_dist or new_dist < 1e-6
 
 
-@pytest.mark.parametrize(['angles', 'error'], _create_tests(n=3, seed=32432432))
+@pytest.mark.parametrize(['angles', 'error'], _create_tests(n=3))
 def test_calibrate_z_phases_workflow_no_options(angles, error):
 
     original_gate = cirq.PhasedFSimGate(**{k: v for k, v in zip(_ANGLES, angles)})
     actual_gate = cirq.PhasedFSimGate(**{k: v + e for k, v, e in zip(_ANGLES, angles, error)})
 
-    sampler = _TestSimulator(original_gate, actual_gate, seed=0)
+    sampler = _TestSimulator(original_gate, actual_gate, seed=_SEED)
     qubits = cirq.q(0, 0), cirq.q(0, 1)
     result, _ = z_phase_calibration_workflow(
         sampler,
@@ -177,6 +180,7 @@ def test_calibrate_z_phases_workflow_no_options(angles, error):
         n_combinations=1,
         n_circuits=1,
         cycle_depths=(1, 2),
+        random_state=_SEED,
     )
 
     for params in result.final_params.values():

cirq-core/cirq/ops/identity.py

@@ -135,6 +135,8 @@ def _mul_with_qubits(self, qubits: Tuple['cirq.Qid', ...], other):
     _rmul_with_qubits = _mul_with_qubits
 
     def _circuit_diagram_info_(self, args) -> Tuple[str, ...]:
+        if self.num_qubits() <= 0:
+            return NotImplemented
         return ('I',) * self.num_qubits()
 
     def _qasm_(self, args: 'cirq.QasmArgs', qubits: Tuple['cirq.Qid', ...]) -> Optional[str]:

cirq-core/cirq/ops/identity_test.py

@@ -214,3 +214,21 @@ def test_identity_commutes():
     assert cirq.commutes(cirq.I, cirq.X)
     with pytest.raises(TypeError):
         cirq.commutes(cirq.I, "Gate")
+
+
+def test_identity_diagram():
+    cirq.testing.assert_has_diagram(
+        cirq.Circuit(cirq.IdentityGate(3).on_each(cirq.LineQubit.range(3))),
+        """
+0: ───I───
+      │
+1: ───I───
+      │
+2: ───I───
+""",
+    )
+    cirq.testing.assert_has_diagram(
+        cirq.Circuit(cirq.IdentityGate(0)()),
+        """
+    I(0)""",
+    )

cirq-core/cirq/ops/phased_x_z_gate.py

@@ -70,9 +70,9 @@ def __init__(
 
     @classmethod
     def from_zyz_angles(cls, z0_rad: float, y_rad: float, z1_rad: float) -> 'cirq.PhasedXZGate':
-        """Create a PhasedXZGate from ZYZ angles.
+        r"""Create a PhasedXZGate from ZYZ angles.
 
-        The returned gate is equivalent to $Rz(z0_rad) Ry(y_rad) Rz(z1_rad)$ (in time order).
+        The returned gate is equivalent to $Rz(z0\_rad) Ry(y\_rad) Rz(z1\_rad)$ (in time order).
         """
         return cls.from_zyz_exponents(z0=z0_rad / np.pi, y=y_rad / np.pi, z1=z1_rad / np.pi)
 

cirq-core/cirq/protocols/circuit_diagram_info_protocol.py

@@ -342,7 +342,7 @@ def _op_info_with_fallback(
     rows: List[LabelEntity] = list(op.qubits)
     if args.label_map is not None:
         rows += protocols.measurement_keys_touched(op) & args.label_map.keys()
-    if info is not None:
+    if info is not None and info.wire_symbols:
         if max(1, len(rows)) != len(info.wire_symbols):
             raise ValueError(f'Wanted diagram info from {op!r} for {rows!r}) but got {info!r}')
         return info

cirq-core/cirq/transformers/gauge_compiling/gauge_compiling.py

@@ -118,6 +118,7 @@ class SameGateGauge(Gauge):
         default=(), converter=lambda g: (g,) if isinstance(g, ops.Gate) else tuple(g)
     )
     swap_qubits: bool = False
+    support_sweep: bool = False
 
     def sample(self, gate: ops.Gate, prng: np.random.Generator) -> ConstantGauge:
         return ConstantGauge(
@@ -127,6 +128,7 @@ def sample(self, gate: ops.Gate, prng: np.random.Generator) -> ConstantGauge:
             post_q0=self.post_q0,
             post_q1=self.post_q1,
             swap_qubits=self.swap_qubits,
+            support_sweep=self.support_sweep,
         )
 
 
@@ -332,6 +334,13 @@ def _parameterize(num_qubits: int, symbol_id: int) -> Dict[str, sympy.Symbol]:
 def _gate_sequence_to_phxz_params(
     gates: Tuple[ops.Gate, ...], xza_by_symbols: Dict[str, sympy.Symbol]
 ) -> Dict[str, float]:
+    identity_gate_in_phxz = {
+        str(xza_by_symbols["x_exponent"]): 0.0,
+        str(xza_by_symbols["z_exponent"]): 0.0,
+        str(xza_by_symbols["axis_phase_exponent"]): 0.0,
+    }
+    if not gates:
+        return identity_gate_in_phxz
     for gate in gates:
         if not has_unitary(gate) or gate.num_qubits() != 1:
             raise ValueError(
@@ -347,11 +356,7 @@ def _gate_sequence_to_phxz_params(
         or ops.I
     )
     if phxz is ops.I:  # Identity gate
-        return {
-            str(xza_by_symbols["x_exponent"]): 0.0,
-            str(xza_by_symbols["z_exponent"]): 0.0,
-            str(xza_by_symbols["axis_phase_exponent"]): 0.0,
-        }
+        return identity_gate_in_phxz
     # Check the gate type, needs to be a PhasedXZ gate.
     if not isinstance(phxz, ops.PhasedXZGate):
         raise ValueError("Failed to convert the gate sequence to a PhasedXZ gate.")

cirq-core/cirq/transformers/gauge_compiling/iswap_gauge.py

@@ -56,6 +56,7 @@ def _rz(self, theta, sgn: int) -> ConstantGauge:
             pre_q1=n_rz if flip_diangonal else rz,
             post_q0=rz if flip_diangonal else n_rz,
             post_q1=n_rz,
+            support_sweep=True,
         )
 
     def sample(self, gate: ops.Gate, prng: np.random.Generator) -> ConstantGauge:
@@ -88,7 +89,12 @@ def _xy_gauge(self, a: float, b: float) -> ConstantGauge:
         xy_a = self._xy(a)
         xy_b = self._xy(b)
         return ConstantGauge(
-            two_qubit_gate=ops.ISWAP, pre_q0=xy_a, pre_q1=xy_b, post_q0=xy_b, post_q1=xy_a
+            two_qubit_gate=ops.ISWAP,
+            pre_q0=xy_a,
+            pre_q1=xy_b,
+            post_q0=xy_b,
+            post_q1=xy_a,
+            support_sweep=True,
         )
 
     def sample(self, gate: ops.Gate, prng: np.random.Generator) -> ConstantGauge:

cirq-core/cirq/transformers/gauge_compiling/iswap_gauge_test.py

@@ -21,3 +21,4 @@
 class TestISWAPGauge(GaugeTester):
     two_qubit_gate = cirq.ISWAP
     gauge_transformer = ISWAPGaugeTransformer
+    sweep_must_pass = True

cirq-core/cirq/transformers/gauge_compiling/spin_inversion_gauge.py

@@ -23,8 +23,8 @@
 
 SpinInversionGaugeSelector = GaugeSelector(
     gauges=[
-        SameGateGauge(pre_q0=ops.X, post_q0=ops.X, pre_q1=ops.X, post_q1=ops.X),
-        SameGateGauge(),
+        SameGateGauge(pre_q0=ops.X, post_q0=ops.X, pre_q1=ops.X, post_q1=ops.X, support_sweep=True),
+        SameGateGauge(support_sweep=True),
     ]
 )
 

cirq-core/cirq/transformers/gauge_compiling/spin_inversion_gauge_test.py

@@ -20,18 +20,22 @@
 class TestSpinInversionGauge_0(GaugeTester):
     two_qubit_gate = cirq.ZZ
     gauge_transformer = SpinInversionGaugeTransformer
+    sweep_must_pass = True
 
 
 class TestSpinInversionGauge_1(GaugeTester):
     two_qubit_gate = cirq.ZZ**0.1
     gauge_transformer = SpinInversionGaugeTransformer
+    sweep_must_pass = True
 
 
 class TestSpinInversionGauge_2(GaugeTester):
     two_qubit_gate = cirq.ZZ**-1
     gauge_transformer = SpinInversionGaugeTransformer
+    sweep_must_pass = True
 
 
 class TestSpinInversionGauge_3(GaugeTester):
     two_qubit_gate = cirq.ZZ**0.3
     gauge_transformer = SpinInversionGaugeTransformer
+    sweep_must_pass = True

cirq-core/cirq/transformers/gauge_compiling/sqrt_iswap_gauge.py

@@ -49,7 +49,12 @@ def _rz(self, theta: float) -> ConstantGauge:
         rz = ops.rz(theta)
         n_rz = ops.rz(-theta)
         return ConstantGauge(
-            two_qubit_gate=ops.SQRT_ISWAP, pre_q0=rz, pre_q1=rz, post_q0=n_rz, post_q1=n_rz
+            two_qubit_gate=ops.SQRT_ISWAP,
+            pre_q0=rz,
+            pre_q1=rz,
+            post_q0=n_rz,
+            post_q1=n_rz,
+            support_sweep=True,
         )
 
     def sample(self, gate: ops.Gate, prng: np.random.Generator) -> ConstantGauge:
@@ -80,7 +85,12 @@ def _xy(self, theta: float) -> ops.PhasedXZGate:
     def _xy_gauge(self, theta: float) -> ConstantGauge:
         xy = self._xy(theta)
         return ConstantGauge(
-            two_qubit_gate=ops.SQRT_ISWAP, pre_q0=xy, pre_q1=xy, post_q0=xy, post_q1=xy
+            two_qubit_gate=ops.SQRT_ISWAP,
+            pre_q0=xy,
+            pre_q1=xy,
+            post_q0=xy,
+            post_q1=xy,
+            support_sweep=True,
         )
 
     def sample(self, gate: ops.Gate, prng: np.random.Generator) -> ConstantGauge:

cirq-core/cirq/transformers/gauge_compiling/sqrt_iswap_gauge_test.py

@@ -20,3 +20,4 @@
 class TestSqrtISWAPGauge(GaugeTester):
     two_qubit_gate = cirq.SQRT_ISWAP
     gauge_transformer = SqrtISWAPGaugeTransformer
+    sweep_must_pass = True

cirq-google/cirq_google/engine/engine.py

@@ -86,8 +86,7 @@ def __init__(
         timeout: Optional[int] = None,
         serializer: Serializer = CIRCUIT_SERIALIZER,
         # TODO(#5996) Remove enable_streaming once the feature is stable.
-        # TODO(#6817): Reenable streaming by default once there's a fix.
-        enable_streaming: bool = False,
+        enable_streaming: bool = True,
     ) -> None:
         """Context and client for using Quantum Engine.