als-statistics/docs/03-analyze/01-cdf/README.md

Modular JS statistics toolkit for Node.js and the browser: descriptive stats, correlations (Pearson/Spearman/Kendall), t-tests & ANOVA (Student/Welch), reliability (Cronbach’s alpha), regression (linear/logistic), clustering (DBSCAN/HDBSCAN), and table/co

<title>Analyze · CDF</title>
<description>Cumulative distribution functions used by other tests.</description>
<keywords>analyze, cdf, exports, cdf.regularizedincompletebeta, x, b, number, cdf.t, df, cdf.f, df1, df2</keywords>

# Analyze · CDF

Cumulative distribution functions used by other tests.

## Exports

- `CDF.regularizedIncompleteBeta(x, a, b): number` – Regularized incomplete beta **Iₓ(a,b)**. Clamps to `[0,1]` when `x≤0` or `x≥1`.
- `CDF.t(x, df): number` – CDF of the **Student t** distribution. `df` must be positive.
- `CDF.f(x, df1, df2): number` – CDF of the **F** distribution. `df1, df2` must be positive.
- `CDF.phi(x): number` – Standard normal CDF **Φ(x)**. Returns `0`/`1` for large negative/positive tails and supports `±Infinity`.