Font properties customization in Matplotlib - Time & Space Complexity

Time Complexity: Font properties customization

O(n)

Understanding Time Complexity

When customizing font properties in matplotlib, it's important to understand how the time to render text changes as we add more text elements or customize more properties.

We want to know how the execution time grows when we change font settings for multiple text items.

Scenario Under Consideration

Analyze the time complexity of the following code snippet.

import matplotlib.pyplot as plt
from matplotlib.font_manager import FontProperties

fig, ax = plt.subplots()
font = FontProperties(family='serif', style='italic', size=12)
n = 10
for i in range(n):
    ax.text(0.5, i*0.1, f'Text {i}', fontproperties=font)
plt.show()

This code creates a plot and adds n text labels with customized font properties.

Identify Repeating Operations

Identify the loops, recursion, array traversals that repeat.

• Primary operation: Adding text labels with font customization inside a loop.
• How many times: The loop runs n times, once for each text label.

How Execution Grows With Input

Each new text label requires setting font properties and rendering, so the total work grows as we add more labels.

Input Size (n)	Approx. Operations
10	10 font setups and text renders
100	100 font setups and text renders
1000	1000 font setups and text renders

Pattern observation: The execution time grows roughly in direct proportion to the number of text items.

Final Time Complexity

Time Complexity: O(n)

This means the time to customize and render fonts grows linearly with the number of text elements.

Common Mistake

[X] Wrong: "Customizing font properties once will speed up adding all text labels."

[OK] Correct: Each text label needs its own font setup and rendering, so the work adds up with more labels.

Interview Connect

Understanding how rendering time grows with more customized text helps you explain performance in data visualization tasks clearly and confidently.

Self-Check

What if we reused the same font properties object without creating a new one inside the loop? How would the time complexity change?