update nb2

Author: sesmart

examples/error_mitigation/on_mitiq/2_Zero_noise_extrapolation_with_mitiq.ipynb

@@ -130,7 +130,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": null,
    "id": "2a0b8339",
    "metadata": {},
    "outputs": [],
@@ -148,7 +148,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": null,
    "id": "d097fc89",
    "metadata": {},
    "outputs": [
@@ -170,7 +170,6 @@
     "\n",
     "circ = Circuit()\n",
     "ideal_evs = []\n",
-    "ideal_stds = []\n",
     "for steps in range(10):\n",
     "    circ+= time_step + time_step\n",
     "    res = qd_exact.run(circ + obs, shots = 0).result()\n",
@@ -181,7 +180,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 6,
+   "execution_count": null,
    "id": "5d969024",
    "metadata": {},
    "outputs": [
@@ -207,7 +206,6 @@
     }
    ],
    "source": [
-    "# plt.errorbar(range(len(ideal_evs)), ideal_evs, ideal_stds, capsize=3, marker='x',linewidth=1)\n",
     "for i in range(num_qubits):\n",
     "    plt.plot(range(10), dat[:,i], label = f'{i}', linestyle = (1,(i+1,1)))\n",
     "plt.legend()\n",