latin hypercube sampling
**Latin Hypercube Sampling (LHS)** is a **stratified sampling technique that divides each factor's range into $N$ equal intervals and places exactly one sample point in each interval** — ensuring marginal uniformity for every factor while maintaining good space-filling properties in the full-dimensional space.
**How LHS Works**
- **Stratification**: Divide each factor range into $N$ equal probability intervals.
- **Random Placement**: Place one point randomly within each interval for each factor.
- **Permutation**: Randomly permute the assignments across factors to create the design.
- **Optimization**: Optimized LHS (MaxiMin, correlation-minimizing) improves multi-dimensional uniformity.
**Why It Matters**
- **Marginal Coverage**: Guarantees that every region of each variable is sampled — no gaps.
- **Efficient**: Provides better coverage than random sampling with the same number of points.
- **Standard Practice**: The default sampling method for computer experiments, sensitivity analysis, and Monte Carlo studies.
**LHS** is **fair sampling across all dimensions** — ensuring that every factor's range is evenly covered regardless of sample size.