matplotlib-users Mailing List for matplotlib

Christian,

As it turns out, I wrote a blog post (for my terrible blog) about using
Designer to create a MPL based GUI (
http://blog.rcnelson.com/building-a-matplotlib-gui-with-qt-designer-part-1/).
I was going to write this up for the MPL docs... But it got really long (3
parts), so I just used my personal site. It got so long because this was
the second time I needed to figure this out, and I wanted to make a very
detailed outline for my own future reference. Unfortunately, I don't have
any experience with Qt5, but I imagine things are similar. I think they
just rearranged the locations of some of the widgets, but I'd be curious to
hear your experience. I gave up on PyQtdesignerplugins. I think it makes
more sense to just use a generic widget as the MPL container.

I would be very happy if you had comments for my Qt designer posts.

Ryan

On Wed, Apr 8, 2015 at 5:47 AM, Christian Ambros <am...@ym...> wrote:

> Hi Ryan,
>
> could you write down, as a tutorial, how you built the example with the qt
> designer?
> In the last hours I read all most everything what can be found on the
> issue of getting matplotlib running with pyqt5 and the designer but as you
> realized yourself, there is little to be found handy.
>
> I'm stuck at a project, which has to use python3, and pyqt5 and am not
> allowed by my boss to fall back to pyqt4 or qt_compat. He wants to make
> sure that we use the latest revisions.
>
> So I#m very pleased to read that someone already set food on this terrain.
> Qt5.4.1 is running and I installed PyQtdesingerplugins, in mind that they
> were written for PyQt4. Are they usable in 5? I added the env-variables to
> my bashrc, did get any changes shown in the designer. Of course I did a
> re-log-in to start fresh, but any changes were noteable.
> What possible ways of embedding matplotlib into a designer base pyqt5-gui
> else, are there?
>
> cheers,
> Christian
>
>
>
> --
> "A little learning never caused anyone's head to explode!"
>
>
> "Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!"
>
>
>
>   On Wednesday, February 18, 2015 11:59 PM, Ryan Nelson <
> rne...@gm...> wrote:
>
>
> Hello list,
>
> A couple months ago, I spent quite a bit of time trying to figure out how
> to use Qt designer create a GUI with an embedded MPL window. Unfortunately,
> the Scipy cookbook page (
> http://wiki.scipy.org/Cookbook/Matplotlib/Qt_with_IPython_and_Designer)
> is very outdated. A recent post (
> http://matplotlib.1069221.n5.nabble.com/Re-Keep-list-of-figures-or-plots-and-flip-through-list-using-UI-td44961.html)
> brought up some questions about a use case very similar to mine, so I redid
> my example and was going to write a quick tutorial for the docs.
>
> Unfortunately, I'm not a Qt guru, so I thought that I would ask on the
> list for some advice.  The OP and I were both interested in being able to
> have a list of figures that you could select from to change the plot
> window. The embedding examples in the docs create subclasses of
> FigureClass* and embed the plotting figure/axes/etc. This works but gets
> tricky, though, when trying to switch plots. Also, for interactive IPython
> work, I didn't like that the plotting objects were mixed in with all the
> QtGui.QWidget attributes, which makes introspective searching painful. My
> solution was to create a dictionary of matplotlib.figure.Figure objects
> that had all of the plotting stuff defined. Then when I select a new plot
> from the list, the old one is removed and a new FigureClass object is
> created using the selected Figure object. Has anyone else successfully done
> something like this? Is there a better way? Also, it seems if I zoom the
> current plot, change to a new plot, and change back, the zoom region is
> retained. Anyone know how to reset the zoom region?
>
> Attached is my example: "window.py" is the Designer-created main window
> and "custommpl.py" is the subclass of the main window that I wrote. It's
> about as short as I could make it.
>
> Thanks
>
> Ryan
>
>
>
>
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Good afternoon, all!

I'm really digging the nbagg backend, and I'm trying to use it to make an
animation. As the subject suggests, though, I'm having some issues with
these features. I'm using Python 3.4, Matplotlib 1.4.3, and IPython 3.1.
Below is a small code sample that emulates my system. The pcolor call can
be substituted for pcolormesh, and I see the same behavior. (Sorry this is
a bit long. I tried to break it up as best as possible.)

#############
#import matplotlib
#matplotlib.use('nbagg')
#%matplotlib nbagg
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animate

class Testing(object):
    def __init__(self, ):
        self.fig = plt.figure()
        array = np.random.rand(4,5)
        #array = np.zeros((4,5))
        self.pc = plt.pcolor(array, edgecolor='k', linewidth=1.)
        self.points = [plt.scatter(np.random.rand(), np.random.rand())]

    def update(self, iter_num):
        array = np.random.rand(4*5)
        self.pc.set_array(array)
        for point in self.points:
            point.remove()
        self.points = [plt.scatter(np.random.rand(), np.random.rand())]

test = Testing()
animate.FuncAnimation(test.fig, test.update, interval=1000, blit=False)
plt.show()
###############

1. As is, this code runs fine with a Qt backend. It also runs fine as a
first call in a notebook if the `show` call is commented out and the
`%matplotlib` line is uncommented. However, if the `show` call is left in
and the `matplotlib.use` call is uncommented, then the pcolor array
changes, but the scatterpoint only shows on the first update and then
disappears forever. What is the difference between these two invocations?

2. With the `%matplotlib` magic uncommented and `show` removed, the first
invocation of this as a cell works fine. Closing the figure (with the red
X) and running the cell again shows two scatter plot points. Running it a
third time shows three scatter plot points. If you call `plt.clf` in the
next cell, I get a series of errors as follows:
_____
ERROR:tornado.application:Exception in callback <bound method
TimerTornado._on_timer of <matplotlib.backends.backend_nbagg.TimerTornado
object at 0x7f894cb10f98>>
Traceback (most recent call last):
  File "/usr/lib64/python3.4/site-packages/tornado/ioloop.py", line 976, in
_run
    return self.callback()
  File "/usr/lib64/python3.4/site-packages/matplotlib/backend_bases.py",
line 1290, in _on_timer
    ret = func(*args, **kwargs)
  File "/usr/lib64/python3.4/site-packages/matplotlib/animation.py", line
925, in _step
    still_going = Animation._step(self, *args)
  File "/usr/lib64/python3.4/site-packages/matplotlib/animation.py", line
784, in _step
    self._draw_next_frame(framedata, self._blit)
  File "/usr/lib64/python3.4/site-packages/matplotlib/animation.py", line
803, in _draw_next_frame
    self._draw_frame(framedata)
  File "/usr/lib64/python3.4/site-packages/matplotlib/animation.py", line
1106, in _draw_frame
    self._drawn_artists = self._func(framedata, *self._args)
  File "<ipython-input-2-f9290d8f6154>", line 22, in update
    point.remove()
  File "/usr/lib64/python3.4/site-packages/matplotlib/artist.py", line 139,
in remove
    self._remove_method(self)
  File "/usr/lib64/python3.4/site-packages/matplotlib/axes/_base.py", line
1479, in <lambda>
    collection._remove_method = lambda h: self.collections.remove(h)
ValueError: list.remove(x): x not in list
______
Why does this happen? Is there a way to close the animation cleanly?

3. If I uncomment the `np.zeros` call, the pcolor array never updates
irrespective of the backend. I see the same behavior with `np.ones` as
well, even if the dtype is set to `float`. Is there are a way to start with
a all-zero pcolor that allow dynamic updates?

4. I'd like to be able to have the animation run until a certain condition
is met. Is there a way to code a clean break for the animation?


As always, any help is most appreciated!

Ryan