matplotlib rcParams not taking effect until after the first plot

[user799595]

trafficstars

Describe the bug matplotlib rcParams not taking effect until after the first plot. Apologies if this is not a jupyter notebook issue!

To Reproduce

I have the following Jupyter Notebook (in percent format)

# %%
import matplotlib.pyplot as plt

# %%
plt.rcParams['figure.figsize'] = (16, 9)

# %%
print(plt.rcParams['figure.figsize']) # prints [16.0, 9.0]
plt.plot(range(100), range(100)) # shows default size (not 16x9) plot

# %%
plt.rcParams['figure.figsize'] = (16, 9)

# %%
plt.plot(range(100), range(100)) # shows large size (16x9) plot

It seems like rcParams has to be set after the first plot in order to work.

Using a fresh conda environment

# Name                    Version                   Build  Channel
ipython                   8.4.0           py310hbe9552e_0    conda-forge
matplotlib                3.5.2           py310hb6292c7_1    conda-forge
notebook                  6.4.12             pyha770c72_0    conda-forge
...

I can also reproduce the issue using Jupyter Lab.

I am not able to reproduce the issue in ipython

# In [1]:
%matplotlib inline
# In [2]:
import matplotlib.pyplot as plt
# In [3]:
plt.rcParams['figure.figsize'] = (16, 9)
# In [4]:
plt.plot(range(100), range(100)) # large size (16x9) plot
# Out[4]:
[<matplotlib.lines.Line2D at 0x115a4f7c0>]
<Figure size 1152x648 with 1 Axes>

Desktop:

• OS: macOS Monterey Version 12.5 (arm64)
• Browser: Firefox

Additional context These issues are different but related

• https://github.com/jupyter/notebook/issues/3385
• https://github.com/ipython/ipython/issues/11098