Bug report

Bug summary

Executing python script with line plotting code from command line on a hidpi 4k resolution display produces low quality UI window plot.

Code for reproduction

$ python3 plot.py

plot.py file contents:

from numpy import random

import matplotlib as mpl
import matplotlib.pyplot as pp

print(mpl.__version__)
print(mpl.get_backend())

pp.figure()
pp.plot(random.randn(250))
pp.grid()
pp.show()

Actual outcome

3.2.1
Qt5Agg

Expected outcome

Expected high quality UI window plots as in Spyder IDE running on the same machine

or similar high quality UI window plots from command line in the previous Kubuntu 19 with matplotlib 3.0.3 and Python 3.7

Matplotlib version

• Operating system: Kubuntu 20.04
• Matplotlib version: 3.2.1
• Matplotlib backend (print(matplotlib.get_backend())): Qt5Agg
• Python version: 3.8.2
• Jupyter version (if applicable):
• Other libraries: