🌳 Day 28: Treemap in Python

 

🌳 Day 28: Treemap in Python

🔹 What is a Treemap?

A Treemap is a hierarchical visualization that uses nested rectangles to show part-to-whole relationships.

• Rectangle size → value

• Rectangle color → category or intensity

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🔹 When Should You Use It?

Use a treemap when:

• You have many categories

• Data is hierarchical

• You want to compare proportions efficiently

Avoid it for precise value comparison.

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🔹 Example Scenario

• Disk space usage by folders

• Company revenue by department & product

• Website traffic by category

Treemaps quickly show dominant contributors.

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🔹 Key Idea Behind It

👉 Area represents magnitude
👉 Nested layout shows hierarchy
👉 Color adds an extra data dimension

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🔹 Python Code (Treemap)

import matplotlib.pyplot as plt
import squarify

labels = ['A', 'B', 'C', 'D', 'E'] 
sizes = [40, 25, 15, 10, 10]

plt.figure(figsize=(8, 5))
squarify.plot( 
    sizes=sizes,
    label=labels, 
    alpha=0.8
)

plt.title('Treemap Example')
plt.axis('off')
plt.show()

📌 Install library if needed:

pip install squarify

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🔹 Output Explanation

• Larger rectangles represent higher values

• Smaller blocks show less contribution

• Total area equals 100%

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🔹 Treemap vs Pie Chart

Aspect	Treemap	Pie Chart
Categories	Many	Few
Hierarchy	Supported	❌
Space usage	Efficient	Limited
Precision	Low	Low

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🔹 Key Takeaways

• Best for large categorical data

• Great alternative to pie charts

• Area-based comparison, not exact values

• Ideal for dashboard summaries