Added SamplePassManager.py

Added SamplePassManager.py

awards/developer_challenge_circuit_optimization_2019/SamplePassManager.py

@@ -0,0 +1,98 @@
+# -*- coding: utf-8 -*-
+
+# Copyright 2019 IBM.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# =============================================================================
+
+from qiskit import execute, Aer, QuantumCircuit
+from qiskit.test.base import dicts_almost_equal
+from qiskit.transpiler.basepasses import AnalysisPass, TransformationPass
+from qiskit.test.mock import FakeMelbourne # NB will need to install dev requirements
+from qiskit.transpiler.passes import TrivialLayout
+from qiskit.transpiler import PassManager
+from qiskit.providers.aer.noise.device import basic_device_noise_model
+
+
+"""
+Your solution needs to comprise of one or more passes that you have written along with
+a PassManager that uses them. The PassManager is allowed to use passes that are already
+included in Qiskit. 
+"""
+
+
+class MyBasicAnalysisPass(AnalysisPass):
+    """Analysis passes look at the DAG to identify some property and then write this
+    to the property set so that it can be accessed by other passes"""
+
+    def run(self, dag):
+        self.property_set['my depth'] = dag.depth()
+
+
+class MyBasicTransformationPass(TransformationPass):
+    """Transformation passes alter the DAG and then return a DAG. They can use properties that
+    have been written to the property set.
+    """
+    def __init__(self, properties):
+        self.properties = properties
+
+    def run(self, dag):
+        dag_depth = self.property_set['my depth']
+        gates = self.properties.gates
+        return dag
+
+
+""" To test your passes you can use the fake backend classes. Your solutions will be tested against
+Yorktown, Ourense and Melbourne, as well as some internal backends. """
+backend = FakeMelbourne()
+properties = backend.properties()
+coupling_map = backend.configuration().coupling_map
+
+
+""" You must submit a pass manager which uses at least one pass you have written. 
+Examples of creating more complex pass managers can be seen in qiskit.transpiler.preset_passmanagers"""
+pass_manager = PassManager()
+pass_manager.append(TrivialLayout(coupling_map))
+pass_manager.append(MyBasicAnalysisPass())
+pass_manager.append(MyBasicTransformationPass(properties))
+
+""" This allows us to simulate the noise a real device has, so that you don't have to wait for jobs to complete
+on the actual backends."""
+noise_model = basic_device_noise_model(properties)
+simulator = Aer.get_backend('qasm_simulator')
+
+
+""" This is the circuit we are going to look at"""
+qc = QuantumCircuit(2, 2)
+qc.h(1)
+qc.measure(0, 0)
+circuits = [qc]
+
+
+result_normal = execute(circuits,
+                        simulator,
+                        coupling_map=coupling_map).result().get_counts()
+
+# NB we include the noise model in the second run
+result_noisy = execute(circuits,
+                       simulator,
+                       noise_model=noise_model,
+                       coupling_map=coupling_map).result().get_counts()
+
+""" Check to see how similar the counts from the two runs are, where delta the allowed difference between
+the counts. Returns an empty string if they are almost equal, otherwise returns an error message which can 
+then be printed."""
+equality_check = dicts_almost_equal(result_normal, result_noisy, delta=1e-8)
+
+if equality_check:
+    print(equality_check)