PyQtGraphDataPlot and MatDataPlot fail to load

Question

hallo,

as soon as I launch rqt_plot using

rqt_plot "topic name"

or

rosrun rqt_plot rqt_plot "topic name"

I get the following errors

rqt_plot.plot: importing PyQtGraphDataPlot
rqt_plot.plot: import of PyQtGraphDataPlot failed
rqt_plot.plot: importing MatDataPlot
rqt_plot.plot: import of MatDataPlot failed

The plotting tools start but I miss the interface buttons. Moreover both the x and y scale don't change according to data. I am using Fedora 18 and groovy. I don't know where to start for debugging because I have never used python. Thanks for your help.

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Originally posted by rick187 on ROS Answers with karma: 63 on 2013-03-15

Post score: 2

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Original comments

Comment by 130s on 2013-03-15:
Can you describe the command you used to run rqt_plot? You can add it to your your original question. Also what version of rqt_common_plugins you're using? You can get the version by $ dpkg -p ros-groovy-rqt-common-plugins on Ubuntu but not sure about Fedora..

Comment by rick187 on 2013-03-15:
I don't know how to retrieve the version. Sorry but It wasn't me who installed ros on this machine and I don't have dpkg on mi Fedora distribution. Do you know any other way? BTW in the package.xml of rqt_plot it says 0.2.10.

Comment by 130s on 2013-03-16:
Actually, I'm seeing PyQtGraphDataPlot import failure on 1 of my machines too (Quantal 64b, Groovy, rqt_plot 0.2.14). Changing the loading order by modifying plot.py still yields the same failure, which indicates order doesn't matter. I'll ask the author.

Answer 1

The messages you saw are not errors, but merely debug messages. They show that you are missing packages for two of the three available ploting backends:

• MatPlotLib

• PyQtGraph

If they are available pre-packaged for your distribution you can simply install them. If not, at least for PyQtGraph it should be enough the download the source code and put it into your Python path.

Since these two are missing, the least comfortable backend has to be used: QwtDataPlot. This one does not feature auto-scaling and other nice features, which the other two backends have. So if you want this, I suggest installing PyQtGraph.

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Originally posted by Dorian Scholz with karma: 391 on 2013-04-08

This answer was ACCEPTED on the original site

Post score: 2

Answer 2

You need to manually install the PyQtGraph.

1. Download the Debian/Ubuntu package on the PyQtGraph website
2. Go to the download directory and type (my version of PyQtGraph is 0.9.8)

dpkg -i python-pyqtgraph_0.9.8-1_all.deb

You can now use

rqt_plot "topic name"

or

rosrun rqt_plot rqt_plot "topic name"

image description http://wiki.ros.org/ROS/Tutorials/UnderstandingTopics?action=AttachFile&do=get&target=rqt_plot.png

There is no more errors.

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Originally posted by Alexandre.Willame with karma: 46 on 2014-12-14

This answer was NOT ACCEPTED on the original site

Post score: 1

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Original comments

Comment by 130s on 2014-12-14:\

You need to manually install the PyQtGraph.

Yes, as documented on the package wiki. Still +1 for reiterating that.