auto odom_data_sub = std::make_shared<diviz::Subscribe<OdometryMsg::OdometryOutput>>("odometrydds_topic");

这段代码是在使用DDS（Data Distribution Service）协议订阅一个名为"odometrydds_topic"的主题，主题中传输的数据类型为OdometryMsg::OdometryOutput。使用auto关键字定义了一个名为odom_data_sub的智能指针，类型为std::shared_ptr<diviz::Subscribe<OdometryMsg::OdometryOutput>>，这个智能指针指向了Subscribe类的一个实例。

相关问题

给下列程序添加注释：void DWAPlannerROS::initialize( std::string name, tf2_ros::Buffer* tf, costmap_2d::Costmap2DROS* costmap_ros) { if (! isInitialized()) { ros::NodeHandle private_nh("~/" + name); g_plan_pub_ = private_nh.advertise<nav_msgs::Path>("global_plan", 1); l_plan_pub_ = private_nh.advertise<nav_msgs::Path>("local_plan", 1); tf_ = tf; costmap_ros_ = costmap_ros; costmap_ros_->getRobotPose(current_pose_); // make sure to update the costmap we'll use for this cycle costmap_2d::Costmap2D* costmap = costmap_ros_->getCostmap(); planner_util_.initialize(tf, costmap, costmap_ros_->getGlobalFrameID()); //create the actual planner that we'll use.. it'll configure itself from the parameter server dp_ = boost::shared_ptr<DWAPlanner>(new DWAPlanner(name, &planner_util_)); if( private_nh.getParam( "odom_topic", odom_topic_ )) { odom_helper_.setOdomTopic( odom_topic_ ); } initialized_ = true; // Warn about deprecated parameters -- remove this block in N-turtle nav_core::warnRenamedParameter(private_nh, "max_vel_trans", "max_trans_vel"); nav_core::warnRenamedParameter(private_nh, "min_vel_trans", "min_trans_vel"); nav_core::warnRenamedParameter(private_nh, "max_vel_theta", "max_rot_vel"); nav_core::warnRenamedParameter(private_nh, "min_vel_theta", "min_rot_vel"); nav_core::warnRenamedParameter(private_nh, "acc_lim_trans", "acc_limit_trans"); nav_core::warnRenamedParameter(private_nh, "theta_stopped_vel", "rot_stopped_vel"); dsrv_ = new dynamic_reconfigure::Server<DWAPlannerConfig>(private_nh); dynamic_reconfigure::Server<DWAPlannerConfig>::CallbackType cb = boost::bind(&DWAPlannerROS::reconfigureCB, this, _1, 2); dsrv->setCallback(cb); } else{ ROS_WARN("This planner has already been initialized, doing nothing."); } }

/**
* @brief 初始化DWAPlannerROS的函数
*
* @param name: 节点名字
* @param tf: tf2_ros::Buffer类型指针，用于获取tf信息
* @param costmap_ros: costmap_2d::Costmap2DROS类型指针，用于获取costmap信息
*/
void DWAPlannerROS::initialize(std::string name, tf2_ros::Buffer* tf, costmap_2d::Costmap2DROS* costmap_ros) {
// 判断是否已经初始化
if (!isInitialized()) {
// 创建私有命名空间
ros::NodeHandle private_nh("~/" + name);

// 创建两个Publisher，用于发布全局规划和局部规划
g_plan_pub_ = private_nh.advertise<nav_msgs::Path>("global_plan", 1);
l_plan_pub_ = private_nh.advertise<nav_msgs::Path>("local_plan", 1);

// 获取tf信息和costmap信息
tf_ = tf;
costmap_ros_ = costmap_ros;
costmap_ros_->getRobotPose(current_pose_);

// 更新costmap
costmap_2d::Costmap2D* costmap = costmap_ros_->getCostmap();

// 初始化planner_util_
planner_util_.initialize(tf, costmap, costmap_ros_->getGlobalFrameID());

// 创建DWAPlanner对象，从参数服务器上获取参数
dp_ = boost::shared_ptr<DWAPlanner>(new DWAPlanner(name, &planner_util_));
if (private_nh.getParam("odom_topic", odom_topic_)) {
odom_helper_.setOdomTopic(odom_topic_);
}

// 设置initialized_为true
initialized_ = true;

// 警告已经被弃用的参数
nav_core::warnRenamedParameter(private_nh, "max_vel_trans", "max_trans_vel");
nav_core::warnRenamedParameter(private_nh, "min_vel_trans", "min_trans_vel");
nav_core::warnRenamedParameter(private_nh, "max_vel_theta", "max_rot_vel");
nav_core::warnRenamedParameter(private_nh, "min_vel_theta", "min_rot_vel");
nav_core::warnRenamedParameter(private_nh, "acc_lim_trans", "acc_limit_trans");
nav_core::warnRenamedParameter(private_nh, "theta_stopped_vel", "rot_stopped_vel");

// 创建dynamic_reconfigure::Server对象，用于动态参数配置
dsrv_ = new dynamic_reconfigure::Server<DWAPlannerConfig>(private_nh);
dynamic_reconfigure::Server<DWAPlannerConfig>::CallbackType cb = boost::bind(&DWAPlannerROS::reconfigureCB, this, _1, 2);
dsrv_->setCallback(cb);
} else {
// 如果已经初始化，输出警告信息
ROS_WARN("This planner has already been initialized, doing nothing.");
}
}

ros::Rate loop_rate(50); ros::NodeHandle nh; CamPose_Pub = nh.advertise<geometry_msgs::PoseStamped>("/Camera_Pose",1); Camodom_Pub = nh.advertise<geometry_msgs::PoseWithCovarianceStamped>("/Camera_Odom", 1); odom_pub = nh.advertise<nav_msgs::Odometry>("/odom", 50); current_time = ros::Time::now(); last_time = ros::Time::now();

这段代码是一个ROS节点的初始化部分，主要完成以下工作：

1. 设置ROS节点的循环频率为50Hz。
2. 创建ROS节点的句柄。
3. 创建三个ROS话题发布者，分别发布相机位姿、相机里程计和机器人里程计信息。
4. 获取当前时间并将其赋值给变量current_time和last_time。

具体解释如下：

第一行代码 `ros::Rate loop_rate(50);` 设置ROS节点的循环频率为50Hz，即ROS节点每秒循环50次。

第二行代码 `ros::NodeHandle nh;` 创建ROS节点的句柄，用于与ROS系统交互。

第三行代码 `CamPose_Pub = nh.advertise<geometry_msgs::PoseStamped>("/Camera_Pose",1);` 创建一个ROS话题发布者，用于发布相机位姿信息。`geometry_msgs::PoseStamped`是一个ROS消息类型，`/Camera_Pose`是话题名称，`1`是发布队列的大小，表示ROS节点可以缓存的最大消息数。

第四行代码 `Camodom_Pub = nh.advertise<geometry_msgs::PoseWithCovarianceStamped>("/Camera_Odom", 1);` 创建一个ROS话题发布者，用于发布相机里程计信息。`geometry_msgs::PoseWithCovarianceStamped`是一个ROS消息类型，`/Camera_Odom`是话题名称，`1`是发布队列的大小。

第五行代码 `odom_pub = nh.advertise<nav_msgs::Odometry>("/odom", 50);` 创建一个ROS话题发布者，用于发布机器人里程计信息。`nav_msgs::Odometry`是一个ROS消息类型，`/odom`是话题名称，`50`是发布队列的大小。

第六行代码 `current_time = ros::Time::now();` 获取当前时间并将其赋值给变量current_time。

第七行代码 `last_time = ros::Time::now();` 获取当前时间并将其赋值给变量last_time。