Feature Engineering

Feature Engineering

Feature Engineering
Use domain knowledge 📕 to create new or transform existing features to improve model performance.
Polynomial 🐙 Features

Create polynomial features, such as, x^2, x^3, etc., to learn non-linear relationship.

images/machine_learning/feature_engineering/feature_engineering/slide_04_01.png
Feature Crossing 🦓

⭐️ Combine 2 or more features to capture non-linear relationship.

  • e.g. combine latitude and longitude into one location feature ‘lat-long'.
Hash 🌿 Encoding

⭐️ Memory-efficient 🧠 technique to convert categorical (string) data into a fixed-size numerical feature vector.

  • Pros:
    • Useful for high-cardinality features where we want to limit the dimensionality.
  • Cons:
    • Hash collisions.
    • Reduced interpretability.

👉 Hash Encoding (Example)

images/machine_learning/feature_engineering/feature_engineering/slide_08_01.png
Binning (Discretization)

⭐️ Group continuous numerical values into discrete categories or ‘bin’.

  • e.g. divide age into groups 18-24, 25-35, 35-45, 45-55, >55 years etc.



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