15 / 30 : add cost function plots over the parameter space

Author: beachdweller

15_optimization/030_Classification_Optimization.ipynb

@@ -325,6 +325,62 @@
     "\n"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Cost function over parameter space ($w_1 \\times w_2$ plane)<br>\n",
+    "매개변수공간 ($w_1 \\times w_2$ 평면) 상의 비용함수\n",
+    "\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def plot_cost_surf(cost_function):\n",
+    "\n",
+    "    w1 = np.linspace(-10.0, 10.0, 20*20+1)\n",
+    "    w2 = np.linspace(-10.0, 10.0, 20*20+1)\n",
+    "\n",
+    "    W1, W2 = np.meshgrid(w1, w2)\n",
+    "    C = np.zeros_like(W1)\n",
+    "\n",
+    "    for i_row in range(W1.shape[0]):\n",
+    "        for j_col in range(W1.shape[1]):\n",
+    "            w = np.array([W1[i_row, j_col], W2[i_row, j_col]])\n",
+    "            C[i_row, j_col] = cost_function(w, data)\n",
+    "\n",
+    "    fig = plt.figure(figsize=(10, 5))\n",
+    "\n",
+    "    ax0 = fig.add_subplot(1, 2, 1)\n",
+    "    ax0.contour(W1, W2, C, cmap='viridis')\n",
+    "    ax0.set_xlabel('$w_1$')\n",
+    "    ax0.set_ylabel('$w_2$')\n",
+    "    ax0.axis('equal')\n",
+    "    ax0.grid(True)\n",
+    "\n",
+    "    ax1 = fig.add_subplot(1, 2, 2, projection='3d')\n",
+    "    ax1.plot_surface(W1, W2, C, cmap='viridis')\n",
+    "    ax1.set_xlabel('$w_1$')\n",
+    "    ax1.set_ylabel('$w_2$')\n",
+    "\n",
+    "    return ax0, ax1\n",
+    "\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "axs = plot_cost_surf(cost_function_first_attempt)\n",
+    "\n"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -496,6 +552,25 @@
     "\n"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Cost function over parameter space ($w_1 \\times w_2$ plane)<br>\n",
+    "매개변수공간 ($w_1 \\times w_2$ 평면) 상의 비용함수\n",
+    "\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "axs = plot_cost_surf(cost_function_step)\n",
+    "\n"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -638,6 +713,25 @@
     "\n"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Cost function over parameter space ($w_1 \\times w_2$ plane)<br>\n",
+    "매개변수공간 ($w_1 \\times w_2$ 평면) 상의 비용함수\n",
+    "\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "axs = plot_cost_surf(cost_function_sigmoid)\n",
+    "\n"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -729,6 +823,25 @@
     "\n"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Cost function over parameter space ($w_1 \\times w_2$ plane)<br>\n",
+    "매개변수공간 ($w_1 \\times w_2$ 평면) 상의 비용함수\n",
+    "\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "axs = plot_cost_surf(cost_function_cross_entropy)\n",
+    "\n"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},