Description
Bug summary
In a certain scenario, adjusting the ylim of a log plot and updating the yticklabels gives numerically incorrect ticks while still plotting the correct values. We were calling get_/set_yticklabels because the cmss10 font didn't have a certain glyph which needed to be replaced, but the bug can be reproduced with the more minimal code below.
Code for reproduction
import matplotlib.pyplot as plt
plt.rcParams.update({
"figure.figsize": (6, 2),
"font.size": 12,
"font.family": "cmss10",
})
x = ['A', 'B', 'C']
y = [10, 1000, 10000]
fig, ax = plt.subplots(layout='constrained')
# Plot and label data
b = ax.bar(x, y)
ax.bar_label(b, y)
# Log scale for vertical axis
ax.set_yscale('log')
# Give a bit extra space for the labels
plt.ylim(None, plt.ylim()[1] * 8)
# Originally was using this to replace special characters in the font
ax.set_yticklabels(ax.get_yticklabels())
plt.savefig('bug-output.png', dpi=300)Actual outcome
The y-axis ticks are incorrectly labeled.
Expected outcome
Additional information
Changing plt.ylim(None, plt.ylim()[1] * 8) to plt.ylim(None, plt.ylim()[1] * 7) (that is, just a bit less extra room) fixes the issue. Granted, most other sets of changes also fix it: this appears to be an extremely idiosyncratic bug, so I'm not clear what the real issue is. Changing the plot size, removing 'constrained', changing the font, removing the ylim statement entirely... these all appear to fix it. It's just the specific combination of parameters that we happened to stumble into this.
Operating system
Mac OS
Matplotlib Version
3.9.3
Matplotlib Backend
macosx
Python version
3.10.2
Jupyter version
N/A
Installation
pip