QubitOperator import from Tangelo, for better encapsulation

tangelo/linq/__init__.py

@@ -18,3 +18,4 @@
 from .simulator import get_backend
 from .target.backend import get_expectation_value_from_frequencies_oneterm
 from .target import backend_info, Backend
+from .noisy_simulation import NoiseModel

tangelo/linq/target/backend.py

@@ -37,19 +37,18 @@
 import numpy as np
 from scipy import stats
 from bitarray import bitarray
-from openfermion.ops import QubitOperator
 
 from tangelo.linq import Gate, Circuit
 from tangelo.linq.helpers.circuits.measurement_basis import measurement_basis_gates
+from tangelo.toolboxes.operators import QubitOperator
 
 
 def get_expectation_value_from_frequencies_oneterm(term, frequencies):
     """Return the expectation value of a single-term qubit-operator, given
     the result of a state-preparation.
 
     Args:
-        term (openfermion-style QubitOperator object): a qubit operator, with
-            only a single term.
+        term (QubitOperator): a single-term qubit operator.
         frequencies (dict): histogram of frequencies of measurements (assumed
             to be in lsq-first format).
 
@@ -82,8 +81,7 @@ def get_variance_from_frequencies_oneterm(term, frequencies):
     """Return the variance of the expectation value of a single-term qubit-operator, given
     the result of a state-preparation.
     Args:
-        term (openfermion-style QubitOperator object): a qubit operator, with
-            only a single term.
+        term (QubitOperator): a single-term qubit operator.
         frequencies (dict): histogram of frequencies of measurements (assumed
             to be in lsq-first format).
     Returns:
@@ -315,8 +313,7 @@ def get_expectation_value(self, qubit_operator, state_prep_circuit, initial_stat
         actual QPU.
 
         Args:
-            qubit_operator (openfermion-style QubitOperator class): a qubit
-                operator.
+            qubit_operator (QubitOperator): the qubit operator.
             state_prep_circuit (Circuit): an abstract circuit used for state preparation.
             initial_statevector (array): The initial statevector for the simulation
             desired_meas_result (str): The mid-circuit measurement results to select for.
@@ -376,8 +373,7 @@ def get_variance(self, qubit_operator, state_prep_circuit, initial_statevector=N
         actual QPU.
 
         Args:
-            qubit_operator (openfermion-style QubitOperator class): a qubit
-                operator.
+            qubit_operator (QubitOperator): the qubit operator.
             state_prep_circuit (Circuit): an abstract circuit used for state preparation.
             initial_statevector (list/array) : A valid statevector in the format
                 supported by the target backend.
@@ -431,8 +427,7 @@ def get_standard_error(self, qubit_operator, state_prep_circuit, initial_stateve
         actual QPU.
 
         Args:
-            qubit_operator (openfermion-style QubitOperator class): a qubit
-                operator.
+            qubit_operator (QubitOperator): the qubit operator.
             state_prep_circuit (Circuit): an abstract circuit used for state preparation.
             initial_statevector (list/array): A valid statevector in the format
                 supported by the target backend.
@@ -452,7 +447,7 @@ def _get_expectation_value_from_statevector(self, qubit_operator, state_prep_cir
         this function directly, please call "get_expectation_value" instead.
 
         Args:
-            qubit_operator (openfermion-style QubitOperator class): a qubit operator.
+            qubit_operator (QubitOperator): the qubit operator.
             state_prep_circuit (Circuit): an abstract circuit used for state preparation (only pure states).
             initial_statevector (array): The initial state of the system
 
@@ -503,7 +498,7 @@ def _get_expectation_value_from_frequencies(self, qubit_operator, state_prep_cir
         using the frequencies of observable states.
 
         Args:
-            qubit_operator (openfermion-style QubitOperator class): a qubitoperator.
+            qubit_operator (QubitOperator): the qubit operator.
             state_prep_circuit (Circuit): an abstract circuit used for state preparation.
             initial_statevector (array): The initial state of the system
             desired_meas_result (str): The mid-circuit measurement results to select for.
@@ -551,7 +546,7 @@ def _get_variance_from_frequencies(self, qubit_operator, state_prep_circuit, ini
         using the frequencies of observable states.
 
         Args:
-            qubit_operator (openfermion-style QubitOperator class): a qubit operator.
+            qubit_operator (QubitOperator): the qubit operator.
             state_prep_circuit (Circuit): an abstract circuit used for state preparation.
             initial_statevector (list/array) : A valid statevector in the format
                 supported by the target backend.
@@ -599,8 +594,7 @@ def get_expectation_value_from_frequencies_oneterm(term, frequencies):
         the result of a state-preparation.
 
         Args:
-            term (openfermion-style QubitOperator object): a qubit operator, with
-                only a single term.
+            term (QubitOperator): a single-term qubit operator
             frequencies (dict): histogram of frequencies of measurements (assumed
                 to be in lsq-first format).
 
@@ -617,8 +611,7 @@ def get_variance_from_frequencies_oneterm(term, frequencies):
         the result of a state-preparation.
 
         Args:
-            term (openfermion-style QubitOperator object): a qubit operator, with
-                only a single term.
+            term (QubitOperator): a single-term qubit operator.
             frequencies (dict): histogram of frequencies of measurements (assumed
                 to be in lsq-first format).