In this quick how-to guide on visualizing metrics from a ROS topic, you will
publish data to a topic in rate mode by executing the command below on
rostopic pub -r 1 /random std_msgs/Float32 5.0
- Click DEVICES > select the device which is publishing /random topic > click Metrics.
- To visualize the data being published by a ROS topic, you will have to first subscribe to the ROS topic by clicking Subscribe. In this example, subscribe to the /random ROS topic.
- To add a new visualization, click Add Cell.
- Click Add a Query.
- Select the ROS topic whose metrics need to be plotted on a graph. In this example, select the /random topic.
- Select the topic’s field like data in this example.
- You may plot multiple functions such as mean, sum, median in the same graph. Click on 1Function button to open the list of fuctions available. Select the functions you want to visualize on the graph like mean in this example, and then click Apply.
- You may change the type of the graph by selecting one of the available graph forms like line, stacked, step-plot or bar. In this example, a Bar graph is selected. To confirm the current settings, click the red colored checkmark at the top-right corner.
- To edit the title of the graph, click the pencil icon at the top right corner of the cell as indicated by 1 in the below image.
- To modify the current graph settings, click the wheel icon at the top right corner of the cell as indicated by 2 in the below image.
- To delete the cell, click on the cross mark at the top right corner of the cell as indicated by 3 in the below picture.
- To change the refresh interval, click Every 60 seconds drop-down list and select your desired interval.
- To change the time range, click Past 5 minutes drop-down list and select your desired range.
- The final graph may look like the one below:
The procedure to visualize the system metrics is the same as
the procedure to visualize metrics from a ROS topic as explained