update some chapter 4 and 5 recipes

Author: benman1

chapter04/stopping_credit_default.ipynb

@@ -901,7 +901,6 @@
    ],
    "source": [
     "from sklearn.metrics import confusion_matrix\n",
-    "from sklearn.metrics import ConfusionMatrixDisplay\n",
     "import pandas as pd\n",
     "\n",
     "cm = confusion_matrix(y_test, preds.mean().numpy() >= 0.5)\n",

chapter05/Making decisions based on knowledge.ipynb

@@ -4107,7 +4107,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.6.7"
+   "version": "3.6.11"
   }
  },
  "nbformat": 4,

chapter05/Solving the n-queens problem.ipynb

@@ -563,13 +563,12 @@
    "outputs": [],
    "source": [
     "import numpy as np\n",
-    "from numba import jit\n",
     "\n",
-    "@jit(nopython=True)\n",
-    "def cost_function(props) -> int:\n",
+    "def cost_function(props):\n",
     "    \"\"\"Given a props vector from a particle,\n",
-    "    a vector of queens' positions, how right are we?\"\"\"\n",
-    "    res: int = 0\n",
+    "    a vector of queens' positions, how right are we?\n",
+    "    \"\"\"\n",
+    "    res = 0\n",
     "    for i1, q1 in enumerate(props[:-1]):\n",
     "        for i2, q2 in enumerate(props[i1+1:], i1+1):\n",
     "            if (q1 != q2) and (abs(i1 - i2) != abs(q1 - q2)):\n",
@@ -1384,7 +1383,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.6.7"
+   "version": "3.6.11"
   }
  },
  "nbformat": 4,