commented project_stats

07_project_stats.py

@@ -3,64 +3,54 @@ from qiskit import (
     QuantumCircuit,
     execute,
     Aer)
-from qiskit.visualization import plot_histogram, plot_bloch_vector
-from matplotlib import pyplot as plt
 from collections import defaultdict
 
-# Use Aer's qasm_simulator
-simulator = Aer.get_backend('qasm_simulator')
+CASE_IDENTICAL = "identical"
+CASE_ORTHOGONAL = "orthogonal"
 
 
-def create_bloch_vector(theta, phi):
-    x = np.sin(theta) * np.cos(phi)
-    y = np.sin(theta) * np.sin(phi)
-    z = np.cos(theta)
-    return [x, y, z]
-
-
-def perform_exp(iterations, case, draw=False):
+def perform_exp(iterations, case):
+    # Use Aer's qasm_simulator
     simulator = Aer.get_backend('qasm_simulator')
     all_counts = defaultdict(int)
 
     for i in range(iterations):
         qc = QuantumCircuit(2, 2)
 
-        # uniform distribution on the sphere
+        # produce angles with uniform distribution on the sphere
         t = round(np.random.uniform(0, 1), 10)
-        theta = np.arccos(1 - 2 * t)
-        phi = round(np.random.uniform(0, 2 * np.pi), 10)
+        theta0 = np.arccos(1 - 2 * t)
+        phi0 = round(np.random.uniform(0, 2 * np.pi), 10)
 
-        CASE_ANGLES = {
-            'identical': (theta, phi),
-            'orthogonal': (theta + np.pi, phi)
-        }
+        # rotate the 0th qubit in (theta, phi)
+        qc.r(theta0, phi0, 0)
 
-        qc.r(theta, phi, 0)
-        theta1, phi1 = CASE_ANGLES[case]
+        # rotate the 1st qubit depending on the case we are exploring...
+        if case == CASE_IDENTICAL:
+            # ... for identical we are rotating the 1st qubit the same angles as
+            # the 0th
+            theta1, phi1 = theta0, phi0
+        elif case == CASE_ORTHOGONAL:
+            # for orthogonal we rotate the 1st qubit in 90 degrees
+            # orthogonal to the first
+            theta1, phi1 = theta0 + np.pi, phi0
+
+        # perform the rotation of the 1st qubit
         qc.r(theta1, phi1, 1)
 
-        # print(theta, phi, phi1)
-
-        if draw:
-            q0 = create_bloch_vector(theta, phi)
-            plot_bloch_vector(q0)
-            plt.show()
-            q1 = create_bloch_vector(theta1, phi1)
-            plot_bloch_vector(q1)
-            plt.show()
-
         # Measure in the Bell's basis
         qc.cx(0, 1)
         qc.h(0)
-        qc.measure([0, 1], [0, 1])
 
-        # print(qc)
+        # measuring maps the 0/1 qubit register to the 0/1 classical register
+        qc.measure([0, 1], [0, 1])
 
         # execute the job
         job = execute(qc, simulator, shots=1)
         result = job.result()
         counts = result.get_counts(qc)
 
+        # update the counts of all experiments with the current run
         for k, v in counts.items():
             all_counts[k] += v
 
@@ -71,7 +61,5 @@ def perform_exp(iterations, case, draw=False):
 
 
 if __name__ == "__main__":
-    # draw produces a Bloch sphere but does not work in this notebook
-
-    perform_exp(iterations=100, case='identical', draw=False)  # same state
-    perform_exp(iterations=100, case='orthogonal', draw=False)  # different orthogonal states
+    perform_exp(iterations=100, case=CASE_IDENTICAL)
+    perform_exp(iterations=100, case=CASE_ORTHOGONAL)