Random

Every evaluate(source, {seed?}) call starts its own random stream, with seed 42 by default. Re-evaluating the same document gives the same samples. The host's random stream, other evaluations, layout, and SVG IDs do not change those draws.

setSeed(7) const points = range(100).map(() => [normal(), normal()]) return <Plot><Points points={points} fill={blue} /></Plot>

Call	Meaning
`setSeed(seed)`	Reset the current stream, including any cached normal sample
`random()`	Uniform fraction in [0,1)
`uniform(lo=0,hi=1)`	Uniform value between finite bounds, with hi greater than lo
`normal(mean=0,stddev=1)`	Normal sample; stddev must be nonnegative, and zero returns mean
`integer(stop)`	Integer from 0 up to, excluding, stop
`integer(start,stop)`	Integer from start up to, excluding, stop

Seeds must be safe integers and are reduced to 32 bits. Integer bounds and their difference must be safe integers, with stop greater than start. The stream uses Mulberry32; normal sampling uses the Marsaglia polar method.

Direct imports of setSeed/random/uniform/normal/integer share one host stream. Use new RNG(seed) for an independent stream with the same methods. Methods are bound, so range(10).map(rng.random) works. Resetting the seed starts the same sequence again. setSeed inside JSX affects only that evaluation's stream.

Sampling happens while constructing elements. Resizing a figure reuses those samples. To create different data, change the seed and evaluate again. A host can also override individual helpers through evaluate(source, {scope}).