mingo
Version:
MongoDB query language for in-memory objects
28 lines (27 loc) • 916 B
JavaScript
import { assert, findInsertIndex, isNumber } from "../../util";
import { $push } from "./push";
const $percentile = (collection, expr, options) => {
const X = $push(collection, expr.input, options).filter(isNumber).sort();
const centiles = $push(expr.p, "$$CURRENT", options).filter(isNumber);
const method = expr.method || "approximate";
return centiles.map((p) => {
assert(
p > 0 && p <= 1,
`percentile value must be between 0 (exclusive) and 1 (inclusive): invalid '${p}'.`
);
const r = p * (X.length - 1) + 1;
const ri = Math.floor(r);
const result = r === ri ? X[r - 1] : X[ri - 1] + r % 1 * (X[ri] - X[ri - 1] || 0);
switch (method) {
case "exact":
return result;
case "approximate": {
const i = findInsertIndex(X, result);
return i / X.length >= p ? X[Math.max(i - 1, 0)] : X[i];
}
}
});
};
export {
$percentile
};