Fix inor typos in chap 8 notebooks

Notebooks/Chap08/8_1_MNIST_1D_Performance.ipynb

@@ -83,6 +83,8 @@
     {
       "cell_type": "code",
       "source": [
+        "!mkdir ./sample_data\n",
+        "\n",
         "args = mnist1d.data.get_dataset_args()\n",
         "data = mnist1d.data.get_dataset(args, path='./sample_data/mnist1d_data.pkl', download=False, regenerate=False)\n",
         "\n",
@@ -136,7 +138,6 @@
         "optimizer = torch.optim.SGD(model.parameters(), lr = 0.05, momentum=0.9)\n",
         "# object that decreases learning rate by half every 10 epochs\n",
         "scheduler = StepLR(optimizer, step_size=10, gamma=0.5)\n",
-        "# create 100 dummy data points and store in data loader class\n",
         "x_train = torch.tensor(data['x'].astype('float32'))\n",
         "y_train = torch.tensor(data['y'].transpose().astype('long'))\n",
         "x_test= torch.tensor(data['x_test'].astype('float32'))\n",
@@ -235,4 +236,4 @@
       }
     }
   ]
-}
+}