Bug report

Bug summary

I use %config InlineBackend.figure_format = 'retina' for sharp images in matplotlib inline mode. However, animations produced with to_jshtml are still using default dpi.

Code for reproduction

Thanks to @story645 for providing the template for this!

import numpy as np
import matplotlib.pyplot as plt
from matplotlib import animation
from IPython.display import HTML


signal = np.random.random((100,))
smoothed = np.convolve(signal, np.full((3,), 1/3), mode='valid')

fig, ax = plt.subplots(figsize=(6,3))
ax.plot(signal, label='signal')
line, = ax.plot(0, smoothed[0], linewidth=3,
                color='C1', label='convolved')
ax.set_xticks(np.arange(0, 100, window_size))
ax.legend()

def animate(i):
    line.set_data(np.arange(i), smoothed[:i])
    return [line]

ani = animation.FuncAnimation(fig, animate, frames=98)

HTML(ani.to_jshtml())

Expected outcome

The animation plot should be as sharp as the image plot.

Matplotlib version

• Operating system: Ubuntu 18.04
• Matplotlib version: 3.0.3
• Matplotlib backend (print(matplotlib.get_backend())): 'module://ipykernel.pylab.backend_inline'
• Python version: 3.6
• Jupyter version (if applicable): 4.4.0
• Other libraries:

mpl installed from pip, I think. ;)