Real math as patchable voltage.
Twenty-eight open-source modules across five plugins that turn real statistical, social, and stochastic processes into control voltage you can patch anywhere in your rack. Sample a distribution as a modulation source, clock a segregation grid into a gate sequencer, let an epidemic curve sweep a filter. Quirky, generative, alive — and the math underneath is the genuine article, not a toy.
Each module is a genuine statistical, agent-based, or dynamical process — a bootstrap resampler, a Granovetter cascade, an SIR epidemic, a reaction-diffusion field — exposed as knobs and control voltage. The output is quirky and alive precisely because the process underneath behaves the way the theory says it should.
Patch them like anything else on your rack. A sampling distribution becomes a modulation source; a segregation grid becomes a generative gate pattern; a drift-diffusion decision fires triggers; an opinion-dynamics model becomes a slow, evolving CV sweep. No stats background needed to enjoy it — and if you do know the math, you can trust it.
Every random module wraps a Mersenne-Twister generator with an explicit on-panel seed, so the same seed is byte-identical across macOS, Windows and Linux. Closed-form quantities use the standard numerical recipes — Lentz continued fractions, BCa bootstrap, Sanger's rule. Patches are plain-JSON .vcv files, and Tape exports its buffer to CSV for R, Python or Julia.
Sample · Frame · Regress · Test · Boot · Lag · Code · Tab · Strata · Cohort · Factor · Seed · Tape · Gauge · Quantity. The full sampling-to-inference chain — draws, regressions, tests and bootstraps — turned into patchable voltage.
Cascade · Discourse · Pareto · Dilemma · Diffusion · Network. Granovetter cascades, opinion dynamics, wealth condensation, iterated dilemmas, and small-world / scale-free networks as evolving control sources.
Outbreak — SIR-style epidemic spread on Watts-Strogatz, Erdős-Rényi and Barabási-Albert graphs. "Flatten the curve" is one patch cable away, its infection wave driving whatever you route it into.
Life · Schelling · Turing. Conway's Game of Life with rule presets, Schelling segregation on a 24 × 24 grid, and Gray-Scott reaction-diffusion traversing spots, stripes and labyrinths.
Prospect · Bandit · DDM. Kahneman-Tversky prospect theory, K-armed bandits with ε-greedy / UCB1 / Thompson sampling, and the Ratcliff drift-diffusion model of decision timing.
Stochast began as a teaching idea, but what it really is is a box of modular-synth instruments made from real mathematics. If you want statistics as a teaching tool instead, that is the job of the separate, browser-based Empiria app — Stochast is for music.
Free, open source, and correct under the hood. No paid tier, no telemetry, no account.
You'll need VCV Rack 2 — a free download for macOS, Windows and Linux from vcvrack.com/Rack. Grab the latest .vcvplugin archives from GitHub releases, drop them into Rack's user plugin folder and restart — the modules appear under the SHLabs brand. Source is on GitHub under GPL-3.0-or-later, with a full methods manual: read it, build it, or send a fix.