Utility functions
Add text
add_text() is a useful function to add text to a plot. It allows you to easily position a text either to the left or right and at the top or bottom of your plot, thanks to aliases on the x and y positional parameters. Using them ensures that your text stays aligned to the left or right of the sub-plot (= ax) you specify. The function is a wrapper around plt.text(), so you can pass any parameter to it that you would pass to plt.text() like fontsize, color, fontweight, etc.
Here are the x and y aliases you can use, with their corresponding positions and alignment:
x aliases
Alias |
Value |
Horizontal alignment (ha) |
|---|---|---|
|
0.0 |
|
|
1.0 |
|
|
0.04 |
|
|
0.97 |
|
|
1.02 |
|
y aliases
Alias |
Value |
Vertical alignment (va) |
|---|---|---|
|
1.01 |
|
|
-0.11 |
|
|
0.96 |
|
|
0.04 |
|
Here is an example of good combinations of aliases to add text to a plot:
By default, the text also fits between the sub-plots by specifying the different axes, as shown in the example below:
from plothist import add_text
# Example from 1d comparison difference plot
add_text("Comparison of two hist with difference plot", ax=ax_main)
add_text("Difference ax", x="right", ax=ax_comparison)
...
Automatic ylabel fontsize
set_fitting_ylabel_fontsize(ax) is a function that will automatically adjust the fontsize of the ylabel so that it fits in the given sub-plot height. It also outputs the fontsize it used, so you can use it to set the same fontsize for other labels.
from plothist import set_fitting_ylabel_fontsize
# Example from pull comparison in model section
set_fitting_ylabel_fontsize(ax_main)
...
Reorder legend entries
The function plot_reorder_legend(ax, order) reorders the legend entries of a given plot. It is useful when you want to have a specific order in your legend.
import matplotlib.pyplot as plt
from plothist import plot_reordered_legend
fig, ax = plt.subplots()
ax.plot([1, 2, 3], label="Line 1")
ax.plot([3, 2, 1], label="Line 2")
# To reorder the legend so that 'Line 2' comes first, use:
plot_reordered_legend(ax, [1, 0])
Warning
We recommend to not alter the order of the legend entries for stacked histograms. By default in plothist, the legend entries are ordered in the same way as the plots are stacked, top to bottom, which improves readability.
Save figure
When saving a figure, doing fig.savefig(path, bbox_inches="tight") works great. It will crop all the unnecessary white space by reducing the final figure size. We recommend this way to save a figure.
If you want to have a fixed figure size (e.g. when putting plots into a LaTeX document), the option matplotlib provides is to call fig.tight_layout() then saving without bbox_inches argument. This will keep the figure size to the default value or the value you specify in plt.figure(), but it will also change the size and position of the sub-plots, which usually have a negative effect on the overall appearance of the figure.
savefig(fig, path) is a function that keeps the figsize you specify, but also keeps the sub-plots as they are. If the sub-plots are too big for the figure, you need to specify a larger figsize and the sub-plots will remain the same size and position, while the final figure will be larger.
For example, below is shown a plot saved with fig.savefig(path, bbox_inches="tight"), then with fig.tight_layout() and saved with fig.savefig(path), and finally with savefig(fig, path) from plothist:
