diff --git a/examples/test_BA.ipynb b/examples/test_BA.ipynb
index 6ae29b3..018c8f5 100644
--- a/examples/test_BA.ipynb
+++ b/examples/test_BA.ipynb
@@ -72,7 +72,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "6cee46c7",
+   "id": "0e69461f-3619-41a5-b202-c6dc8e2fc778",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -104,7 +104,9 @@
     "    for im in rec.images.values():\n",
     "        cam = rec.cameras[im.camera_id]\n",
     "        for p in im.points2D:\n",
-    "            cost = pyceres.factors.ReprojErrorCost(cam.model, im.cam_from_world, p.xy)\n",
+    "            cost = pycolmap.cost_functions.ReprojErrorCost(\n",
+    "                cam.model, im.cam_from_world, p.xy\n",
+    "            )\n",
     "            prob.add_residual_block(\n",
     "                cost, loss, [rec.points3D[p.point3D_id].xyz, cam.params]\n",
     "            )\n",
@@ -185,7 +187,7 @@
     "    for im in rec.images.values():\n",
     "        cam = rec.cameras[im.camera_id]\n",
     "        for p in im.points2D:\n",
-    "            cost = pyceres.factors.ReprojErrorCost(cam.model, p.xy)\n",
+    "            cost = pycolmap.cost_functions.ReprojErrorCost(cam.model, p.xy)\n",
     "            pose = im.cam_from_world\n",
     "            params = [\n",
     "                pose.rotation.quat,\n",
diff --git a/examples/test_PGO.ipynb b/examples/test_PGO.ipynb
index 338c73a..0093b92 100644
--- a/examples/test_PGO.ipynb
+++ b/examples/test_PGO.ipynb
@@ -79,14 +79,14 @@
     "loss = pyceres.TrivialLoss()\n",
     "costs = []\n",
     "for i in range(num):\n",
-    "    cost = pyceres.factors.PoseGraphRelativeCost(i_from_j[i], np.eye(6))\n",
+    "    cost = pycolmap.cost_functions.MetricRelativePoseErrorCost(i_from_j[i], np.eye(6))\n",
     "    costs.append(cost)\n",
     "    j = (i + 1) % num\n",
     "    params = [\n",
-    "        i_from_w_opt[j].rotation.quat,\n",
-    "        i_from_w_opt[j].translation,\n",
     "        i_from_w_opt[i].rotation.quat,\n",
     "        i_from_w_opt[i].translation,\n",
+    "        i_from_w_opt[j].rotation.quat,\n",
+    "        i_from_w_opt[j].translation,\n",
     "    ]\n",
     "    prob.add_residual_block(cost, loss, params)\n",
     "    prob.set_manifold(i_from_w_opt[i].rotation.quat, pyceres.EigenQuaternionManifold())\n",
@@ -129,7 +129,7 @@
     "loss = pyceres.TrivialLoss()\n",
     "costs = []\n",
     "for i in range(num):\n",
-    "    cost = pyceres.factors.PoseGraphAbsoluteCost(i_from_w[i], np.eye(6))\n",
+    "    cost = pycolmap.cost_functions.AbsolutePoseErrorCost(i_from_w[i], np.eye(6))\n",
     "    costs.append(cost)\n",
     "    pose = i_from_w_opt[i]\n",
     "    prob.add_residual_block(cost, loss, [pose.rotation.quat, pose.translation])\n",