chore: doc

packages/math/src/math.js

@@ -178,6 +178,12 @@ export const randomNumber = (min, max) => {
 // smooth(er)?step assumes unit
 export const smoothstep = (x) => x * x * (3 - 2 * x);
 export const smootherstep = (x) => x * x * x * (x * (x * 6 - 15) + 10);
+/**
+ * Probabilistic behavior. Every `period` seconds, return `true`.
+ *
+ * @param {Number} elapsed The time that's passed.
+ * @param {Number} period The frequency of probabilistic behavior.
+ */
 export const spontaneous = (elapsed, period) => Math.random() < 1 / (period / elapsed);
 export const sub = (l, r) => l - r;
 export const toRad = (a) => a * PI_180;