-p_X = p.sum(1)
-p_Z = p.sum(0)
-p_X_given_Z = p / p.sum(0, keepdim = True)
-p_Z_given_X = p / p.sum(1, keepdim = True)
-q_X_given_Z = q / q.sum(0, keepdim = True)
-q_Z_given_X = q / q.sum(1, keepdim = True)
+# q_X_given_Z = q_XZ / q_XZ.sum(0, keepdim = True)
+q_Z_given_X = q_XZ / q_XZ.sum(1, keepdim=True)