UserWarning: The figure layout has changed to tight plt.tight_layout()

UserWarning: The figure layout has changed to tight refers to a warning message commonly seen in the Matplotlib library when working with Python plots. In earlier versions of Matplotlib, figures were not automatically adjusted to fit their contents tightly by default. The `plt.tight_layout()` function is used to alleviate this issue and make sure that all the elements within a figure are arranged in a way that maximizes available space without overlapping.

When you encounter this warning, it suggests that you should call `plt.tight_layout()` after creating or modifying your plot structure, like adding or removing subplots, to ensure a clean and well-formatted final output. This function helps to optimize the layout for publication or presentation purposes.

To use it, simply include the following line of code where appropriate in your script:

# 在创建或调整完图形元素之后添加此行
plt.tight_layout()