Possible to live the data from rosbag

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Hello,

I see 3 way to display rosbag data in streaming :

1) with rqt_bag

You can use the executable "rqt_bag" (or "rosrun rqt_bag rqt_bag") to open a rqt GUI where you can load a rosbag -> right click on a topic -> view -> plot -> check the data you want on the graph on the new rqt_plot GUI and click play.

You will see a graph of your data with a red bar (the timeline) to see the current data. It's not a live streaming (all data appear on the graph) but it's the easiest method.

2) with rqt_plot

You can play a bag file and open a rqt_plot at the same time with 3 terminal.

On terminal 1, launch a roscore (command "roscore")

On terminal 2, launch play your bag file (command "rosbag play bagname")

On terminal 3, launch rqt_plot (command "rqt_plot" or "rosrun rqt_plot rqt_plot")

On the rqt_plot GUI, type the topic you want to display and adjust the axes.

You can also use PlotJuggler

3) with roslaunch

You can use the previous method but instead of launching "rqt_plot", just launch rqt (with "rqt" or "rosrun rqt rqt")

Then go to plugin > visualization > Plot

Choose the topic you want.

Click on perspective > Export... and save the perspective file where you want (an easy path if possible).

Then you need a roslaunch file that look like this :

 <launch>
  <node name="<name_of_your_rosbag_node>" pkg="rosbag" type="rosbag" args="play <name_of_your_rosbag>"/>
  <node name="<name_of_your_gui_node>" pkg="rqt" type="rqt" args="--perspective-file <your_perspective_file>"/>
</launch>

Then execute your launch file with "roslaunch name_of_your_launch_file".

Your data in live streaming with rqt_plot should open.