hz_measure_nodelet.cpp

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#include <pluginlib/class_list_macros.h>
#include "jsk_topic_tools/hz_measure_nodelet.h"

#include "std_msgs/Float32.h"

namespace jsk_topic_tools
{
  void HzMeasure::onInit()
  {
    pnh_ = getPrivateNodeHandle();
    if (!pnh_.getParam("message_num", average_message_num_)) {
      average_message_num_ = 10; // defaults to 10
    }
    hz_pub_ = pnh_.advertise<std_msgs::Float32>("output", 1);
    sub_ = pnh_.subscribe<topic_tools::ShapeShifter>("input", 1,
                                                     &HzMeasure::inputCallback, this);
  }

  void HzMeasure::inputCallback(const boost::shared_ptr<topic_tools::ShapeShifter const>& msg)
  {
    ros::Time now = ros::Time::now();
    buffer_.push(now);
    if (buffer_.size() > average_message_num_) {
      ros::Time oldest = buffer_.front();
      double whole_time = (now - oldest).toSec();
      double average_time = whole_time / (buffer_.size() - 1);
      std_msgs::Float32 output;
      output.data = 1.0 / average_time;
      hz_pub_.publish(output);
      buffer_.pop();
    }
    else {
      NODELET_DEBUG("there is no enough messages yet");
    }
  }
  
}

typedef jsk_topic_tools::HzMeasure HzMeasure;
PLUGINLIB_EXPORT_CLASS(HzMeasure, nodelet::Nodelet)