How to use multiple font sizes in one label in Python Matplotlib?

To use multiple font sizes in one label in Python Matplotlib, you can combine different text elements or use LaTeX formatting with size commands. This allows creating visually appealing labels with varying emphasis.

Method 1: Using LaTeX Size Commands

The most effective way is using LaTeX size commands like \large, \small, and \huge within a single title ?

import numpy as np
import matplotlib.pyplot as plt

plt.rcParams["figure.figsize"] = [8, 4]
plt.rcParams["figure.autolayout"] = True

x = np.linspace(-5, 5, 100)
y = np.cos(x)

plt.plot(x, y, 'b-', linewidth=2)

# Multiple font sizes in one title using LaTeX
plt.title(r"$\huge{Function:}$ $\large{y = \cos(x)}$ $\small{(continuous)}$", 
          fontsize=14)
plt.grid(True, alpha=0.3)

plt.show()

Method 2: Using Text Annotations

Place multiple text elements at different positions with varying font sizes ?

import numpy as np
import matplotlib.pyplot as plt

fig, ax = plt.subplots(figsize=(8, 4))

x = np.linspace(-2, 2, 100)
y = x**2

ax.plot(x, y, 'r-', linewidth=2)

# Multiple text elements with different sizes
ax.text(0.5, 0.95, 'Quadratic', transform=ax.transAxes, 
        fontsize=20, weight='bold', ha='center')
ax.text(0.5, 0.85, 'Function', transform=ax.transAxes, 
        fontsize=16, ha='center')
ax.text(0.5, 0.75, 'y = x²', transform=ax.transAxes, 
        fontsize=12, ha='center', style='italic')

plt.grid(True, alpha=0.3)
plt.show()

Method 3: Combining Text with Different Properties

Use formatted strings with matplotlib's text rendering for mixed sizing ?

import numpy as np
import matplotlib.pyplot as plt

fig, ax = plt.subplots(figsize=(8, 4))

x = np.linspace(0, 4*np.pi, 100)
y = np.sin(x)

ax.plot(x, y, 'g-', linewidth=2)

# Using fontdict for different parts
title_text = "Sine Wave Analysis"
subtitle_text = "Amplitude: 1, Period: 2?"

ax.text(0.5, 0.95, title_text, transform=ax.transAxes,
        fontsize=18, weight='bold', ha='center')
ax.text(0.5, 0.88, subtitle_text, transform=ax.transAxes,
        fontsize=12, ha='center', color='gray')

plt.grid(True, alpha=0.3)
plt.show()

Comparison of Methods

LaTeX Size Commands

Common LaTeX size commands you can use:

• \tiny - Smallest size

• \small - Small text

• \large - Large text

• \Large - Larger text

• \huge - Huge text

Conclusion

Use LaTeX size commands for simple mixed-size titles in mathematical contexts. For complex layouts with precise control, combine multiple text elements with different font properties and positions.