Add integ tests for result types for local and aws simulators and exa…

examples/bell.py

@@ -1,3 +1,16 @@
+# Copyright 2019-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+
 import boto3
 from braket.aws import AwsQuantumSimulator, AwsQuantumSimulatorArns
 from braket.circuits import Circuit

examples/bell_result_types.py

@@ -0,0 +1,62 @@
+# Copyright 2019-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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 braket.circuits import Circuit, Observable
+from braket.devices import LocalSimulator
+
+device = LocalSimulator()
+
+print("Example for shots=0")
+# Result types can be requested in the circuit
+# Example of result types for shots=0
+bell = (
+    Circuit()
+    .h(0)
+    .cnot(0, 1)
+    .probability(target=[0])
+    .expectation(observable=Observable.Z(), target=[1])
+    .amplitude(state="00")
+    .state_vector()
+)
+
+# State vector and amplitude can only be requested when shots=0 for a simulator
+# When shots=0 for a simulator, probability, expectation, variance are the exact values,
+# not calculated from measurements
+# Users cannot request Sample as a result when shots=0
+result = device.run(bell).result()
+print("Marginal probability for target 0 in computational basis:", result.values[0])
+print("Expectation of target 1 in the computational basis:", result.values[1])
+print("Amplitude of state 00:", result.values[2])
+print("State vector:", result.values[3])
+
+print("\nExample for shots>0")
+# Example of result types for shots > 0
+bell = (
+    Circuit()
+    .h(0)
+    .cnot(0, 1)
+    .probability()
+    .expectation(observable=Observable.Y() @ Observable.X(), target=[0, 1])
+    .variance(observable=Observable.Y() @ Observable.X(), target=[0, 1])
+    .sample(observable=Observable.Y() @ Observable.X(), target=[0, 1])
+)
+
+# When shots>0 for a simulator, probability, expectation, variance are calculated from measurements
+# Users can request sample as a result when shots > 0
+result = device.run(bell, shots=100).result()
+print("Probability of all states in computational basis:", result.values[0])
+print("Expectation of target 0, 1 in the basis of Pauli-Y @ Pauli-X:", result.values[1])
+print("Variance of target 0, 1 in the basis of Pauli-Y @ Pauli-X:", result.values[2])
+print("Samples of target 0, 1 in the basis of Pauli-Y @ Pauli-X:", result.values[3])
+
+# Probability, sample, expectation, and variance are also supported for QPU devices

examples/debug_bell.py

@@ -1,3 +1,16 @@
+# Copyright 2019-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+
 import logging
 import sys
 

examples/local_bell.py

@@ -1,3 +1,16 @@
+# Copyright 2019-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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 braket.circuits import Circuit
 from braket.devices import LocalSimulator
 

src/braket/circuits/circuit.py

@@ -48,7 +48,6 @@ class Circuit:
     """
 
     _ALL_QUBITS = "ALL"  # Flag to indicate all qubits in _qubit_observable_mapping
-    _EXISTING_QUBITS = "EXISTING"  # Flag to indicate existing qubits in _qubit_observable_mapping
 
     @classmethod
     def register_subroutine(cls, func: SubroutineCallable) -> None:
@@ -147,17 +146,20 @@ def basis_rotation_instructions(self) -> List[Instruction]:
             if isinstance(result_type, ObservableResultType)
         )
 
+        added_observables_targets = set()
         for return_type in observable_return_types:
-            target: List[int] = return_type.target
             observable: Observable = return_type.observable
-            if not target:
-                # There will be only one result type in observable_return_types,
-                # and its observable acts on all qubits
-                for target in self._moments.qubits:
-                    basis_rotation_instructions += Circuit._observable_to_instruction(
-                        observable, target
-                    )
-            else:
+            targets: List[List[int]] = [return_type.target] if return_type.target else [
+                QubitSet(qubit) for qubit in self._moments.qubits
+            ]
+
+            for target in targets:
+                # only add gates for observables and targets that
+                # have not been processed
+                str_observables_target = f"{observable}; {target}"
+                if str_observables_target in added_observables_targets:
+                    continue
+                added_observables_targets.add(str_observables_target)
                 basis_rotation_instructions += Circuit._observable_to_instruction(
                     observable, target
                 )
@@ -267,18 +269,22 @@ def _add_to_qubit_observable_mapping(self, result_type: ResultType) -> None:
             observable = result_type.observable
         else:
             return
-        targets = result_type.target if result_type.target else Circuit._EXISTING_QUBITS
+
+        targets = result_type.target or self._qubit_observable_mapping.keys()
         all_qubits_observable = self._qubit_observable_mapping.get(Circuit._ALL_QUBITS)
 
         for target in targets:
             current_observable = all_qubits_observable or self._qubit_observable_mapping.get(target)
             if current_observable and current_observable != observable:
                 raise ValueError(
                     f"Existing result type for observable {current_observable} for target {target}"
-                    + f"conflicts with observable {observable} for new result type"
+                    f" conflicts with observable {observable} for new result type"
                 )
-            self._qubit_observable_mapping[target] = observable
-        self._qubit_observable_mapping[Circuit._EXISTING_QUBITS] = observable
+            if result_type.target:
+                self._qubit_observable_mapping[target] = observable
+
+        if not result_type.target:
+            self._qubit_observable_mapping[Circuit._ALL_QUBITS] = observable
 
     def add_instruction(
         self,

src/braket/circuits/observables.py

@@ -171,10 +171,10 @@ def __init__(self, observables: List[Observable]):
             >>> t2.factors
             (Z('qubit_count': 1), Y('qubit_count': 1), X('qubit_count': 1))
 
-        Note: You must provide the list of observables for the tensor product to be evaluated 
-        in the order that you want the tensor product to be calculated. 
-        For `TensorProduct(observables=[ob1, ob2, ob3])`, the tensor product's matrix is the 
-        result of the tensor product of `ob1`, `ob2`, `ob3`, or `np.kron(np.kron(ob1.to_matrix(), 
+        Note: You must provide the list of observables for the tensor product to be evaluated
+        in the order that you want the tensor product to be calculated.
+        For `TensorProduct(observables=[ob1, ob2, ob3])`, the tensor product's matrix is the
+        result of the tensor product of `ob1`, `ob2`, `ob3`, or `np.kron(np.kron(ob1.to_matrix(),
         ob2.to_matrix()), ob3.to_matrix())`.
         """
         self._observables = tuple(observables)
@@ -329,6 +329,10 @@ def _get_eigendecomposition(self) -> Dict[str, np.ndarray]:
             }
         return Hermitian._eigenpairs[mat_key]
 
+    def __repr__(self):
+        matrix_str = np.array2string(self.to_matrix()).replace("\n", ",")
+        return f"{self.name}('qubit_count': {self.qubit_count}, 'matrix': {matrix_str})"
+
 
 Observable.register_observable(Hermitian)
 

src/braket/circuits/result_types.py

@@ -137,8 +137,8 @@ def __copy__(self):
 class Probability(ResultType):
     """Probability in the computational basis as the requested result type.
 
-    It can be the probability of all states if no targets are specified, or the marginal 
-    probability of a restricted set of states if only a subset of all qubits are specified as 
+    It can be the probability of all states if no targets are specified, or the marginal
+    probability of a restricted set of states if only a subset of all qubits are specified as
     targets.
 
     For `shots>0`, this is calculated by measurements. For `shots=0`, this is supported
@@ -228,7 +228,7 @@ def __init__(self, observable: Observable, target: QubitSetInput = None):
                 operate only on 1 qubit and it is applied to all qubits in parallel.
 
         Raises:
-            ValueError: If the observable's qubit count does not equal the number of target 
+            ValueError: If the observable's qubit count does not equal the number of target
             qubits, or if target=None and the observable's qubit count is not 1.
 
         Examples:
@@ -295,7 +295,7 @@ def __init__(self, observable: Observable, target: QubitSetInput = None):
                 operate only on 1 qubit and it is applied to all qubits in parallel.
 
         Raises:
-            ValueError: If the observable's qubit count is not equal to the number of target 
+            ValueError: If the observable's qubit count is not equal to the number of target
             qubits, or if target=None and the observable's qubit count is not 1.
 
         Examples:
@@ -345,7 +345,7 @@ class Variance(ObservableResultType):
     """Variance of specified target qubit set and observable as the requested result type.
 
     If no targets are specified, the observable must operate only on 1 qubit and it
-    is applied to all qubits in parallel. Otherwise, the number of targets specified 
+    is applied to all qubits in parallel. Otherwise, the number of targets specified
     must equal the number of qubits that the observable can be applied to.
 
     For `shots>0`, this is calculated by measurements. For `shots=0`, this is supported
@@ -363,7 +363,7 @@ def __init__(self, observable: Observable, target: QubitSetInput = None):
                 operate only on 1 qubit and it is applied to all qubits in parallel.
 
         Raises:
-            ValueError: If the observable's qubit count does not equal the number of target 
+            ValueError: If the observable's qubit count does not equal the number of target
             qubits, or if target=None and the observable's qubit count is not 1.
 
         Examples:

test/integ_tests/conftest.py

@@ -17,7 +17,6 @@
 import pytest
 from botocore.exceptions import ClientError
 from braket.aws.aws_session import AwsSession
-from braket.circuits import Circuit
 
 
 @pytest.fixture(scope="session")
@@ -71,18 +70,3 @@ def s3_prefix():
 @pytest.fixture(scope="module")
 def s3_destination_folder(s3_bucket, s3_prefix):
     return AwsSession.S3DestinationFolder(s3_bucket, s3_prefix)
-
-
-@pytest.fixture(scope="session")
-def bell_state_and_tolerances():
-    return Circuit().h(0).cnot(0, 1), {"00": (0.4, 0.6), "11": (0.4, 0.6)}
-
-
-@pytest.fixture(scope="session")
-def state_110_and_most_common():
-    return Circuit().x(0).x(1).i(2), "110"
-
-
-@pytest.fixture(scope="session")
-def state_001_and_most_common():
-    return Circuit().i(0).i(1).x(2), "001"