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I have a bag with messages published on two different topics and I need to take this data, compute them and then publish to another topic. How can i subscribe to a bag without knowing the internal code of it (to create for example the callbacks of the subscribers)?
Run the Rosbag normally and grab the topic you want as it is published again.
Rostopic echo /cmd_vel >> save_this.txt
(Above is just an example of how to do it, after starting the playing of Rosbag.)
Ok, so you are suggesting to extract directly the data. So then instead of a subscriber to the bag, I would need a publisher which has to read the file just extracted from the bag, and compute every line with some math I have to apply, right? If I am correct, could you tell me a way on how to use data from a text file in a publisher node? Thank you very much in advance
If it is a rosbag you can use rosbag play your_recorder_bag.baglike here: http://wiki.ros.org/rosbag/Commandline to use it as "a publisher" with messages you can subscribe and convert like you want in other node
Asked: 2022-04-08 10:57:54 -0500
Seen: 81 times
Last updated: Apr 08 '22
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