Show epochs as integers on x-axis (#241)

* Show epochs as integers on x-axis

* Update ch07/01_main-chapter-code/previous_chapters.py

* remove extra s

* modify exercise plots

* update chapter 7 plot

* resave ch07 for better file diff

ch05/01_main-chapter-code/ch05.ipynb

@@ -1347,6 +1347,8 @@
    ],
    "source": [
     "import matplotlib.pyplot as plt\n",
+    "from matplotlib.ticker import MaxNLocator\n",
+    "\n",
     "\n",
     "def plot_losses(epochs_seen, tokens_seen, train_losses, val_losses):\n",
     "    fig, ax1 = plt.subplots(figsize=(5, 3))\n",
@@ -1357,6 +1359,7 @@
     "    ax1.set_xlabel(\"Epochs\")\n",
     "    ax1.set_ylabel(\"Loss\")\n",
     "    ax1.legend(loc=\"upper right\")\n",
+    "    ax1.xaxis.set_major_locator(MaxNLocator(integer=True))  # only show integer labels on x-axis\n",
     "\n",
     "    # Create a second x-axis for tokens seen\n",
     "    ax2 = ax1.twiny()  # Create a second x-axis that shares the same y-axis\n",
@@ -2455,7 +2458,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.10.6"
+   "version": "3.11.4"
   }
  },
  "nbformat": 4,