Revert NoiseModel.from_dict (Qiskit#2222)

qiskit_aer/noise/noise_model.py

@@ -20,7 +20,8 @@
 
 import numpy as np
 
-from qiskit.circuit import Instruction, Delay
+from qiskit.circuit import QuantumCircuit, Instruction, Delay, Reset
+from qiskit.circuit.library.generalized_gates import PauliGate, UnitaryGate
 from qiskit.providers import QubitProperties
 from qiskit.providers.exceptions import BackendPropertyError
 from qiskit.providers.models.backendproperties import BackendProperties
@@ -959,6 +960,105 @@ def to_dict(self, serializable=False):
 
         return ret
 
+    @staticmethod
+    def from_dict(noise_dict):
+        """
+        Load NoiseModel from a dictionary.
+        Args:
+            noise_dict (dict): A serialized noise model.
+        Returns:
+            NoiseModel: the noise model.
+        Raises:
+            NoiseError: if dict cannot be converted to NoiseModel.
+        """
+        warn(
+            "from_dict has been deprecated as of qiskit-aer 0.15.0"
+            " and will be removed no earlier than 3 months from that release date.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+
+        def inst_dic_list_to_circuit(dic_list):
+            num_qubits = max(max(dic["qubits"]) for dic in dic_list) + 1
+            circ = QuantumCircuit(num_qubits)
+            for dic in dic_list:
+                if dic["name"] == "reset":
+                    circ.append(Reset(), qargs=dic["qubits"])
+                elif dic["name"] == "kraus":
+                    circ.append(
+                        Instruction(
+                            name="kraus",
+                            num_qubits=len(dic["qubits"]),
+                            num_clbits=0,
+                            params=dic["params"],
+                        ),
+                        qargs=dic["qubits"],
+                    )
+                elif dic["name"] == "unitary":
+                    circ.append(UnitaryGate(data=dic["params"][0]), qargs=dic["qubits"])
+                elif dic["name"] == "pauli":
+                    circ.append(PauliGate(dic["params"][0]), qargs=dic["qubits"])
+                else:
+                    with catch_warnings():
+                        filterwarnings(
+                            "ignore",
+                            category=DeprecationWarning,
+                            module="qiskit_aer.noise.errors.errorutils",
+                        )
+                        circ.append(
+                            UnitaryGate(
+                                label=dic["name"], data=_standard_gate_unitary(dic["name"])
+                            ),
+                            qargs=dic["qubits"],
+                        )
+            return circ
+
+        # Return noise model
+        noise_model = NoiseModel()
+
+        # Get error terms
+        errors = noise_dict.get("errors", [])
+
+        for error in errors:
+            error_type = error["type"]
+
+            # Add QuantumError
+            if error_type == "qerror":
+                circuits = [inst_dic_list_to_circuit(dics) for dics in error["instructions"]]
+                noise_ops = tuple(zip(circuits, error["probabilities"]))
+                qerror = QuantumError(noise_ops)
+                qerror._id = error.get("id", None) or qerror.id
+                instruction_names = error["operations"]
+                all_gate_qubits = error.get("gate_qubits", None)
+                if all_gate_qubits is not None:
+                    for gate_qubits in all_gate_qubits:
+                        # Add local quantum error
+                        noise_model.add_quantum_error(
+                            qerror, instruction_names, gate_qubits, warnings=False
+                        )
+                else:
+                    # Add all-qubit quantum error
+                    noise_model.add_all_qubit_quantum_error(
+                        qerror, instruction_names, warnings=False
+                    )
+
+            # Add ReadoutError
+            elif error_type == "roerror":
+                probabilities = error["probabilities"]
+                all_gate_qubits = error.get("gate_qubits", None)
+                roerror = ReadoutError(probabilities)
+                # Add local readout error
+                if all_gate_qubits is not None:
+                    for gate_qubits in all_gate_qubits:
+                        noise_model.add_readout_error(roerror, gate_qubits, warnings=False)
+                # Add all-qubit readout error
+                else:
+                    noise_model.add_all_qubit_readout_error(roerror, warnings=False)
+            # Invalid error type
+            else:
+                raise NoiseError("Invalid error type: {}".format(error_type))
+        return noise_model
+
     def _instruction_names_labels(self, instructions):
         """Return two lists of instruction name strings and label strings."""
         if not isinstance(instructions, (list, tuple)):

releasenotes/notes/revert_noise_from_dict-b3a85bf28582a9b1.yaml

@@ -0,0 +1,5 @@
+---
+deprecations:
+  - |
+    Reverting NoiseModel.from_dict temporary to extend deprecation period
+    for qiskit-ibm-runtime, but we will remove again in the future release

test/terra/noise/test_noise_model.py

@@ -21,7 +21,7 @@
 from qiskit_aer.backends import AerSimulator
 from qiskit_aer.noise import NoiseModel
 from qiskit_aer.noise.device.models import _excited_population
-from qiskit_aer.noise.errors import PauliError, PauliLindbladError
+from qiskit_aer.noise.errors import QuantumError, PauliError, PauliLindbladError
 from qiskit_aer.noise.errors.standard_errors import amplitude_damping_error
 from qiskit_aer.noise.errors.standard_errors import kraus_error
 from qiskit_aer.noise.errors.standard_errors import pauli_error
@@ -31,6 +31,8 @@
 
 import qiskit
 from qiskit.circuit import QuantumRegister, ClassicalRegister, QuantumCircuit
+from qiskit.circuit.library.standard_gates import IGate, XGate
+from qiskit.circuit.library.generalized_gates import PauliGate
 from qiskit.compiler import transpile
 from qiskit.transpiler import CouplingMap, Target
 from qiskit.providers import QubitProperties, BackendV2, Options
@@ -416,6 +418,25 @@ def test_pauli_lindblad_error_sampling_equiv(self):
         probs2 = [counts2.get(i, 0) / shots for i in ["00", "01", "10", "11"]]
         np.testing.assert_allclose(probs1, probs2, atol=5e-2)
 
+    def test_from_dict(self):
+        noise_ops_1q = [((IGate(), [0]), 0.9), ((XGate(), [0]), 0.1)]
+
+        noise_ops_2q = [
+            ((PauliGate("II"), [0, 1]), 0.9),
+            ((PauliGate("IX"), [0, 1]), 0.045),
+            ((PauliGate("XI"), [0, 1]), 0.045),
+            ((PauliGate("XX"), [0, 1]), 0.01),
+        ]
+
+        noise_model = NoiseModel()
+        with self.assertWarns(DeprecationWarning):
+            noise_model.add_quantum_error(QuantumError(noise_ops_1q), "h", [0])
+            noise_model.add_quantum_error(QuantumError(noise_ops_1q), "h", [1])
+            noise_model.add_quantum_error(QuantumError(noise_ops_2q), "cx", [0, 1])
+            noise_model.add_quantum_error(QuantumError(noise_ops_2q), "cx", [1, 0])
+            deserialized = NoiseModel.from_dict(noise_model.to_dict())
+            self.assertEqual(noise_model, deserialized)
+
 
 if __name__ == "__main__":
     unittest.main()