rqt_plot: "edit curves and line axes" does not work

[ahendrix]

When I push the "edit curves and line axes" button, I get a stacktrace:

Traceback (most recent call last):
  File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_qt4.py", line 474, in edit_parameters
    figureoptions.figure_edit(axes, self)
  File "/usr/lib/pymodules/python2.7/matplotlib/backends/qt4_editor/figureoptions.py", line 132, in figure_edit
    icon=get_icon('qt4_editor_options.svg'), apply=apply_callback)
  File "/usr/lib/pymodules/python2.7/matplotlib/backends/qt4_editor/formlayout.py", line 511, in fedit
    dialog = FormDialog(data, title, comment, icon, parent, apply)
  File "/usr/lib/pymodules/python2.7/matplotlib/backends/qt4_editor/formlayout.py", line 427, in __init__
    self.formwidget.setup()
  File "/usr/lib/pymodules/python2.7/matplotlib/backends/qt4_editor/formlayout.py", line 399, in setup
    widget.setup()
  File "/usr/lib/pymodules/python2.7/matplotlib/backends/qt4_editor/formlayout.py", line 374, in setup
    widget.setup()
  File "/usr/lib/pymodules/python2.7/matplotlib/backends/qt4_editor/formlayout.py", line 281, in setup
    field.addItems(value)
TypeError: QComboBox.addItems(QStringList): argument 1 has unexpected type 'list'

ros-groovy-rqt-plot 0.2.16-0
ros-groovy-python-qt-binding 0.2.9-0
Ubuntu Precise 12.04

[ablasdel]

@DorianScholz Have you seen this issue before?

[DorianScholz]

I have not seen this before. But I'm not using the matplot backend, I very much recommend using the pyqtgraph backend. I just could not make it the default, because it is not in the Ubuntu repos.

[ablasdel]

@DorianScholz Since Matplot has so many issues what would the harm be in depending on the best of the lot and setting it as default?

[DorianScholz]

I'd be OK with this. But the best of the lot to me is pyqtgraph, which is not available from the Ubuntu repos and needs to be manually downloaded and installed. So depending on it is not as easy as depending on matplotlib. But if you feel this would be OK, go ahaed!

[ablasdel]

The Manual bit probably makes it a no go. Would the qwtplot possibly work? It is in the ubunto repos and would be better than matplot right?

[ablasdel]

Also wouldn't adding items to a combo box be at the Qt widget layer? I don't think this is a backend problem at all.

[DorianScholz]

The exception happens inside of the matplotlib Qt4 backend, so this is a problem with matplotlib.
The last line of the exception reads:
QComboBox.addItems(QStringList): argument 1 has unexpected type 'list'

Conversion from "list" to "QStringList" is automatic in PyQt/PySide (if the correct SIP API levels are set).
So it would be important to know whether this happens running with PySide or PyQt bindings, which I cannot see from the backtrace.
@ahendrix If you could reproduce this with forced bindings (rqt -b pyside / rqt -b pyqt), this would be very helpful.

[130s]

My 2 cents - Given that pyqtgraph provides the best functionality but not in Ubuntu repo, but its .deb is available, I would say from user's point of view that it's acceptable to make pyqtgraph as default for rqt_plot, and ask users for manual installation, which can be done by a few clicks.

I'm not yet sure if it's acceptable though from other aspects (ROS package release criteria if any etc.), but at least buildfarm shouldn't be a problem as long as pyqtgraph isn't included in dependency.

Another idea (not sure if it's feasible) is write script in rosdep rule to wget and dpkg the .deb file.

[ahendrix]

From a packaging perspective, rqt_plot should have a dependency on its default backend. Otherwise, it will be broken by default, which will result is a lot of angry users and more bug reports to deal with.

If we want to make pyqtgraph the default backend, we should set up a rosdep for pyqtgraph, and possibly get the deb incorporated into the ROS repositories. It's also worth thinking about how users on non-Ubuntu distributions get pyqtgraph; it's probably worth trying to set up rosdeps for Fedora and OSX.

On a more general note, this bug should be very easy to reproduce: select matplotlib as the backend and push the "edit curves and axes" button.

If matplotlib isn't a supported backend (and it's really sounding like it isn't), it should be removed.

[130s]

I gave it a try to make rosdep rule and keep failing (question asked).

[130s]

Looks like rosdep no longer supports scripted rule http://www.ros.org/reps/rep-0111.html#bash-scripts that's why I kept failing.

[ahendrix]

We already have a deb of pyqtgraph; what's the problem with getting it incorporated into the ROS deb repository? This is done for many other tools, such as openni, collada-dom, etc.

[ablasdel]

This seems like a good option. Is there a process for how we can complete this or who we need to talk too?

[ahendrix]

I think you should contact Tully; he does most of the maintenance on the ROS deb repositories.

[ablasdel]

I contacted him and will post when I get a response.

[130s]

I had no idea if putting a 3rd party .deb into ROS deb repo was possible. Thanks for letting us know Austin.

[tfoote]

Picking up random debs is not something to take lightly. Our general rule is that we will import backports of packages submitted/accepted upstream. We do not want to become a complete linux distribution, picking arbitrary versions of all packages and doing the full integration. Also the package should be generally available for other platforms, and it needs to stick to ABI compatibility. If you need something like this I would recommend creating a ros wrapper package such that it will be scoped and installed into /opt/ros/DISTRO. This will keep the maintenance scope down and not interfere with potential future versions released into upstream.

[ablasdel]

The pyqtgraph source is available here: http://www.pyqtgraph.org/
They seem to have set up an "unofficial" github version of the source here: https://github.com/lcampagn/pyqtgraph but it is 2 years old.

I'll look around to see if there is a more recent public github or svn repo somewhere that they are using.

[ablasdel]

Took a moment this morning to search. The code lives here: https://code.launchpad.net/pyqtgraph creating a release repo pointed at this should be doable. I will look into that today.

[ablasdel]

Bit of a roadblock it looks like bloom doesn't support bazaar repos as vcs_types. @wjwwood Am I reading the bloom code correctly on this?

[wjwwood]

bloom does not support bzr.

I would take a pull request to add support though. bloom is designed to take different upstream vcs and vcstools supports bzr, so there aren't a lot of road blocks to adding support I think, but the other, easier solution is to use tar, and use one of their release tarballs.

[wjwwood]

Honestly, I don't know how we got completely side tracked away from the point of this issue, which is that matplotlib, which is the default backend, is broken. Reguardless of getting better support for pyqtgraph and switching it to the default, we should probably fix or remove matplotlib if it doesn't work...

[ablasdel]

Oh sorry for not being clear that was my intention as soon as we don't need matplotlib we would excise it. (or at least that is what I was assuming)

[ablasdel]

Newest info: The tools that currently exist don't handle building/installing pure python packages.

@dirk-thomas I was told that stdeb might be the answer to getting this done and that you would be able to give some insight into getting this built properly.

linking the tar that we are trying to build to keep easy track: http://www.pyqtgraph.org/downloads/pyqtgraph-0.9.7.tar.gz

[ablasdel]

I am going to have to pull myself off of issues for plugins I didn't implement for now due to hardware and time concerns. @dirk-thomas @DorianScholz I think this is a very important issue could someone please pick it up?

[130s]

Back to the original reported issue (since I just saw the same error when I clicked on "check" sign that should open a config dialog for the graph), I investigated a little about the status of matplotlib and this issue might not be going to be resolved in the library on Precise; Looks like similar error was fixed but that was after Precise was released and its .deb version has been staying the same 1.1.1.

I just added recommendation of installing pyqtgraph to wiki. Maybe adding console output for the recommendation is one way to work this around.

[vincentrou]

I do not reproduce this issue on Ubuntu 12.04 with :
ros-hydro-rqt-plot 0.3.12
ros-hydro-python-qt-binding 0.2.16
python-matplotlib 1.1.1
Should be closed ?

[trainman419]

Confirmed fixed in Indigo on Ubuntu 14.04 as well:
ros-indigo-rqt-plot 0.3.12
ros-indigo-python-qt-binding 0.2.17
python-matplotlib 1.3.1

[dirk-thomas]

Thank you both for checking.

I will close the ticket. If anyone is still having this problem please feel free to comment here.