remove broken event loop code

[ianhi]

fixes: #79

A potential future ipympl specific improvement was mentioned in #79 (comment)

[ianhi]

@Michael-Equi can you confirm this fixes your issue. You can install with pip install git+https://github.com/ianhi/ipympl.git@patch-1

[Michael-Equi]

That appears to have worked in eliminating the error although pause now seems to be preventing the rendering of my graph in my jupyter lab.

[lgtm-com]

This pull request introduces 1 alert when merging a03a5cb into 3372f9b - view on LGTM.com

new alerts:

• 1 for Unused import

[ianhi]

That appears to have worked in eliminating the error although pause now seems to be preventing the rendering of my graph in my jupyter lab.

But not in notebook? Do you have a short example of what you're doing?

[Michael-Equi]

I have tried running this live plot example in both Jupiter land and Jupiter notebook

import numpy as np 
from mpl_toolkits.mplot3d import Axes3D
from matplotlib import pyplot as plt
 
 
 
def update_line(hl, new_data):
    xdata, ydata, zdata = hl._verts3d
    hl.set_xdata(np.append(xdata, new_data[0]))
    hl.set_ydata(np.append(ydata, new_data[1]))
    hl.set_3d_properties(np.append(zdata, new_data[2]))

 
 
map = plt.figure()
map_ax = Axes3D(map)
map_ax.autoscale(enable=True, axis='both', tight=True)
 
# # # Setting the axes properties
map_ax.set_xlim3d([0.0, 10.0])
map_ax.set_ylim3d([0.0, 10.0])
map_ax.set_zlim3d([0.0, 10.0])
 
hl, = map_ax.plot3D([0], [0], [0])
 
update_line(hl, (2,2, 1))
plt.draw()
plt.show(block=False)
plt.pause(1)
 
update_line(hl, (5,5, 5))
plt.show(block=False)
plt.pause(2)
 
update_line(hl, (8,1, 4))
plt.show(block=True)

In both cases it does not render the plot until the final plt.show

[ianhi]

maybe this is similar to: #258 does the solution using async from the stackoverflow post in that issue work for you?

As for how to make your example work I think we'll need input from someone with stronger matplotlib skills than me.

[Michael-Equi]

I ended up getting it working with something like the following

from matplotlib import pyplot as plt
from matplotlib.animation import FuncAnimation
from random import randrange
from threading import Thread
import time

class LiveGraph:
    def __init__(self):
        self.x_data, self.y_data = [], []
        self.figure = plt.figure()
        self.line, = plt.plot(self.x_data, self.y_data)
        self.animation = FuncAnimation(self.figure, self.update, interval=1000)
        self.th = Thread(target=self.thread_f, daemon=True)
        self.th.start()

    def update(self, frame):
        self.line.set_data(self.x_data, self.y_data)
        self.figure.gca().relim()
        self.figure.gca().autoscale_view()
        return self.line,

    def show(self):
        plt.show()

    def thread_f(self):
        x = 0
        while True:
            self.x_data.append(x)
            x += 1
            self.y_data.append(randrange(0, 100))   
            time.sleep(1)  

g = LiveGraph()
g.show()

[martinRenou]

@ianhi is this ready to be merged?

[ianhi]

I'm not sure. It removes the error in the original issue but #266 (comment) certainly doesn't seem right and I don't think that this is expected behavior for plt.pause:

%matplotlib widget
from matplotlib import pyplot as plt

plt.figure()
plt.plot([1,2,3])
plt.pause(2)    
plt.plot([3,2,1])
plt.close()

compared to the same from ipython:

[ianhi]

So basically I think this removes the error, but doesn't fix the problem. Also, I don't know how to fix the underlying problem, or even what the underlying problem is.

[martinRenou]

I see. I wonder if the plt.pause() does not block the comm message. It would be interesting to see if this issue happens in the nbagg backend, see if it's a regression in ipympl.

[ianhi]

Notebook suffers the same affliction.

Since nbagg also doesn't implement the methods so I think we're falling back to the same thing. So it looks like merging this would make it so ipympl is even with nbagg, but both would be a regression from non-web backends.

[ianhi]

I think this is related to #258 which I also don't really understand.

[ianhi]

Superseded by #291

[martinRenou]

@ianhi really sorry for this, it didn't occur to me that it was the same PR.

[ianhi]

@ianhi really sorry for this, it didn't occur to me that it was the same PR.

No worries! I had sorta left this one hanging anyways

[thomasaarholt]

Wow, I didn't even check to see if this was here! Sorry!