Basic Math Concepts – Categorical Cross Entropy relevancy in Neural Network

1. Minimum Math Concepts:

Concept Why It’s Needed
Probability Understanding class probabilities (e.g., [0.7, 0.2, 0.1])
Logarithm (log base e) The formula uses natural log (ln) to calculate loss
One-hot encoding Target values are represented like [1, 0, 0]
Summation / Looping To compute total loss over multiple samples

2. Categorical Cross Entropy Formula:

For a single sample with N classes:

Loss = − Σi=1N yi ⋅ log(ŷi)

Where:

  • yi is the actual (one-hot) label.
  • y^i is the predicted probability for class i.

If only one class is correct (one-hot), the formula simplifies to:

Loss = −log(predicted probability for correct class)

Categorical Cross-Entropy relevancy in Neural Network – Visual Roadmap