Distribution Lab shows 28 probability distributions interactively — as preparation for GLMs and Bayesian models in brms. Which distribution fits which data? For each distribution: description, use cases, parameter explanation, brms usage and technical details. Category tabs (top) select the distribution group.
Distribution buttons below select the specific distribution.
Sliders on the left adjust parameters in real time. X lock button (topbar): Freezes the x-axis so that when changing parameters (e.g. μ or σ) the shape change is directly visible — instead of the axis rescaling. Resets automatically when switching distributions. ⊞ Relations button opens a large overview map with all 21 distributions of the Distribution Lab and their connections: special cases, limits, constructions. Orientation in the distribution zoo. Mean (blue), Median (green), Mode (orange) as vertical dashed lines. Each moment independently toggleable. For Gamma and Beta: toggle between brms (μ, φ) and classical (α, β). Automatic conversion. The brms parametrisation is more intuitive: you set the mean directly.

The "Usage in brms" section shows for each distribution: as likelihood (family syntax, link) and as prior (prior() syntax) — including typical parametrisations. ZI-Beta and ZOIB: point masses at 0/1 as red bars, Beta component as curve. Hurdle-Gamma and Hurdle-Lognormal: point mass at 0 as a red bar, positive component as a curve on (0, ∞) instead of [0,1]. Bar chart of the PMF. Mode = tallest bar.