Fixing 'matplotlib non-GUI backend' error in Jupyter notebook

If you're encountering the 'matplotlib non-GUI backend' error in Jupyter notebook, it means that the default backend for matplotlib is not compatible with Jupyter's non-GUI environment. However, you can easily fix this error by changing the backend to one that is compatible with Jupyter.

Step 1: Check your current backend

Before changing the backend, you should check what your current backend is. To do this, run the following code in a Jupyter notebook cell:

import matplotlib.pyplot as plt
print(plt.get_backend())

This will print the name of your current backend. If the backend is 'agg', 'svg', or 'pdf', then you need to change it to a GUI backend.

Step 2: Install a GUI backend

If you don't have a GUI backend installed, you'll need to install one. The most common GUI backend is 'TkAgg', which can be installed by running the following command in your terminal:

pip install tk

Once you've installed 'TkAgg', you can set it as your backend by adding the following code to your Jupyter notebook:

import matplotlib
matplotlib.use('TkAgg')

Step 3: Restart the kernel

After changing the backend, you'll need to restart the kernel for the changes to take effect. To do this, go to the 'Kernel' menu in Jupyter notebook and select 'Restart Kernel'.

Once you've completed these steps, you should no longer encounter the 'matplotlib non-GUI backend' error in Jupyter notebook.