Wigner function functionality: Fixed an error

qiskit/tools/qcvv/tomography.py

@@ -717,13 +717,11 @@ def fit_tomography_data(data, method=None, options=None):
 # Wigner function tomography
 ###############################################################
 
-def build_wigner_circuits(Q_program, name, phis, thetas, qubits,
+def build_wigner_circuits(q_program, name, phis, thetas, qubits,
                           qreg, creg, silent=False):
-
     """Create the circuits to rotate to points in phase space
-
     Args:
-        Q_program (QuantumProgram): A quantum program to store the circuits.
+        q_program (QuantumProgram): A quantum program to store the circuits.
         name (string): The name of the base circuit to be appended.
         phis (np.matrix[[complex]]):
         thetas (np.matrix[[complex]]):
@@ -733,77 +731,69 @@ def build_wigner_circuits(Q_program, name, phis, thetas, qubits,
         creg (ClassicalRegister): the classical register containing bits to
                                     store measurement outcomes.
         silent (bool, optional): hide verbose output.
-        
+
     Returns: A list of names of the added wigner function circuits.
-
     """
-
-    orig = Q_program.get_circuit(name)
+    orig = q_program.get_circuit(name)
     labels = []
     points = len(phis[0])
-
-
+
     for point in range(points):
         label = '_wigner_phase_point'
         label += str(point)
-        circuit = Q_program.create_circuit(label, [qreg], [creg])
-        c_index = 0
-
+        circuit = q_program.create_circuit(label, [qreg], [creg])
+
         for qubit in range(len(qubits)):
             circuit.u3(thetas[qubit][point], 0,
-                       phis[qubit][point],qreg[qubits[qubit]])
-            circuit.measure(qreg[qubits[qubit]],creg[qubits[qubit]])
-        
-        Q_program.add_circuit(name+label, orig+circuit)
+                       phis[qubit][point], qreg[qubits[qubit]])
+            circuit.measure(qreg[qubits[qubit]], creg[qubits[qubit]])
+
+        q_program.add_circuit(name + label, orig + circuit)
         labels.append(name+label)
-    
+
     if not silent:
         print('>> created Wigner function circuits for "%s"' % name)
     return labels
 
 
-def wigner_data(Q_result, name, meas_qubits, labels, shots=None):
-
+def wigner_data(q_result, meas_qubits, labels, shots=None):
     """Get the value of the Wigner function from measurement results.
-        
+
     Args:
-        Q_result (Result): Results from execution of a state tomography
+        q_result (Result): Results from execution of a state tomography
                             circuits on a backend.
-        name (string): The name of the base state preparation circuit.
         meas_qubits (list[int]): a list of the qubit indexes measured.
         labels : a list of names of the circuits
-
+        shots (int): number of shots
+
     Returns: The values of the Wigner function at measured points in
             phase space
-
     """
-
     num = len(meas_qubits)
-    
+
     dim = 2**num
-    P = [0.5+0.5*np.sqrt(3),0.5-0.5*np.sqrt(3)]
+    p = [0.5+0.5*np.sqrt(3), 0.5-0.5*np.sqrt(3)]
     parity = 1
-    
+
     for i in range(num):
-        parity = np.kron(parity,P)
-    
-    W = [0]*len(labels)
+        parity = np.kron(parity, p)
+
+    w = [0]*len(labels)
     wpt = 0
-    counts = [marginal_counts(Q_result.get_counts(circ), meas_qubits)
+    counts = [marginal_counts(q_result.get_counts(circ), meas_qubits)
               for circ in labels]
     for entry in counts:
-        x =[0]*dim
-        
+        x = [0]*dim
+
         for i in range(dim):
             if bin(i)[2:].zfill(num) in entry:
                 x[i] = float(entry[bin(i)[2:].zfill(num)])
-
-            if shots is None:
-                shots = np.sum(x)
-
-                for i in range(dim):
-                W[wpt] = W[wpt]+(x[i]/shots)*parity[i]
-
-            wpt += 1
-
-    return W
+
+        if shots is None:
+            shots = np.sum(x)
+
+        for i in range(dim):
+            w[wpt] = w[wpt]+(x[i]/shots)*parity[i]
+        wpt += 1
+
+    return w