Update LQR colab to use .name and .id attributes of indexers.

PiperOrigin-RevId: 481915877
Change-Id: Iba79523422a442f3ca4793587936e05797d43e40

python/LQR.ipynb

@@ -226,7 +226,7 @@
         "    if not isinstance(camera, mujoco.MjvCamera):\n",
         "      camera_id = camera\n",
         "      if isinstance(camera_id, str):\n",
-        "        camera_id = self._model.name2id(camera_id, 'camera')\n",
+        "        camera_id = _model.camera(camera_id).id\n",
         "      if camera_id \u003c -1:\n",
         "        raise ValueError('camera_id cannot be smaller than -1.')\n",
         "      if camera_id \u003e= self._model.ncam:\n",
@@ -769,13 +769,11 @@
         "data.qpos = qpos0\n",
         "mujoco.mj_forward(model, data)\n",
         "jac_com = np.zeros((3, nv))\n",
-        "torso_body_id = mujoco.mj_name2id(model, mujoco.mjtObj.mjOBJ_BODY, 'torso')\n",
-        "mujoco.mj_jacSubtreeCom(model, data, jac_com, torso_body_id)\n",
+        "mujoco.mj_jacSubtreeCom(model, data, jac_com, model.body('torso').id)\n",
         "\n",
         "# Get the Jacobian for the left foot.\n",
         "jac_foot = np.zeros((3, nv))\n",
-        "foot_body_id = mujoco.mj_name2id(model, mujoco.mjtObj.mjOBJ_BODY, 'foot_left')\n",
-        "mujoco.mj_jacBodyCom(model, data, jac_foot, None, foot_body_id)\n",
+        "mujoco.mj_jacBodyCom(model, data, jac_foot, None, model.body('foot_left').id)\n",
         "\n",
         "jac_diff = jac_com - jac_foot\n",
         "Qbalance = jac_diff.T @ jac_diff"
@@ -805,10 +803,7 @@
       "outputs": [],
       "source": [
         "# Get all joint names.\n",
-        "joint_names = [\n",
-        "    mujoco.mj_id2name(model, mujoco.mjtObj.mjOBJ_JOINT, i)\n",
-        "    for i in range(model.njnt)\n",
-        "]\n",
+        "joint_names = [model.joint(i).name for i in range(model.njnt)]\n",
         "\n",
         "# Get indices into relevant sets of joints.\n",
         "root_dofs = range(6)\n",