Fixed two tiny python typos

Author: mdiephuis

Chapter5_LossFunctions/LossFunctions.ipynb

@@ -814,7 +814,7 @@
       "    \"\"\"vectorized for numpy\"\"\"\n",
       "    sol = np.zeros_like(price)\n",
       "    ix = price*pred < 0 \n",
-      "    sol[ix] = coef*pred**2 - sign(price[ix])*pred + abs(price[ix])\n",
+      "    sol[ix] = coef*pred**2 - np.sign(price[ix])*pred + abs(price[ix])\n",
       "    sol[ ~ix ] = abs( price[~ix] - pred )\n",
       "    return sol\n",
       "\n",
@@ -845,7 +845,7 @@
       "plt.title( \"Least-squares prediction vs. Bayes action prediction\" )\n",
       "plt.plot( X, ls_coef_*X + ls_intercept, label =\"Least-squares prediction\")\n",
       "plt.xlim( X.min(), X.max())\n",
-      "plot( trading_signals, opt_predictions, label =\"Bayes action prediction\")\n",
+      "plt.plot( trading_signals, opt_predictions, label =\"Bayes action prediction\")\n",
       "plt.legend( loc=\"upper left\" );"
      ],
      "language": "python",