Constant
A fixed number that does not change - opposite of a variable.
- Named constants: π, e, i.
- In ML, hyperparameters are constants per run.
- Distinguishing fixed-vs-varying is the heart of model design.
When to use: Identifying what is tunable vs. what is set up front.
Example: MSE = (1/n)·Σ(y−ŷ)²: n is a constant, y and ŷ vary across samples.