Rqt_plot and rqt_graph error

Course Support ROS Basics In 5 Days (Python)
1

Hi, I’m doing Unit 8: How to debug ROS programs. While trying to do exercise 9.2 and typing the following in the rqt_plot:

image
image1147×69 39.8 KB

I get the following output in the WebShell:
image
image1183×409 25.5 KB

No plot shows up, and when doing the next exercise with rqt_graph I get the similar output in WebShell but no output in rqt_graph.
I’ve followed the instructions very carefully when doing these exercises but it still doesn’t work properly.

Thank you in advance for help!

2

Hi, thank you for bringing this to our attention, we are currently working on this fix.

3

We have already created a fix for this issue.
In the next system update it will be fixed.

As a workaround if you dont want to wait, you can edit this file:

sudo vim /opt/ros/noetic/lib/python3/dist-packages/rqt_plot/rosplot.py

line 201
Change >>>>slot_num = string.atoi(rest[:rest.find(’]’)])
To>>>>>>>>>slot_num = int(rest[:rest.find(’]’)])

You will have to make this change eahc time you want to use the rqt_plot in a new simulation I’m affraid.

This is a known issue of ROS binay that we just detected and we had to install by source with this fix ;).
Thanks for reporting the bug

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