aaronrene / knowtation public
kmeans.mjs
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sha256:65ccb454656ea5acdea0a10e559b78bcde1eb6ff753ecc2911bc99d1c3d7cadd feat(calendar): enforce agent context tiers in retrieval AP… Human minor ⚠ breaking 1 day ago
1 /**
2 * Minimal k-means for embedding vectors (Issue #1 Phase C8).
3 */
4
5 function distSq(a, b) {
6 let s = 0;
7 const n = Math.min(a.length, b.length);
8 for (let i = 0; i < n; i++) {
9 const d = a[i] - b[i];
10 s += d * d;
11 }
12 return s;
13 }
14
15 function mean(vectors) {
16 if (!vectors.length) return [];
17 const dim = vectors[0].length;
18 const acc = new Array(dim).fill(0);
19 for (const v of vectors) {
20 for (let i = 0; i < dim; i++) acc[i] += v[i] || 0;
21 }
22 return acc.map((x) => x / vectors.length);
23 }
24
25 /**
26 * @param {{ id: string, vector: number[] }[]} points
27 * @param {number} k
28 * @param {number} maxIter
29 * @returns {{ labels: number[], centroids: number[][] }}
30 */
31 export function kmeans(points, k, maxIter = 25) {
32 if (!points.length || k < 1) return { labels: [], centroids: [] };
33 k = Math.min(k, points.length);
34 const dim = points[0].vector.length;
35 const centroids = [];
36 const step = Math.max(1, Math.floor(points.length / k));
37 for (let c = 0; c < k; c++) {
38 centroids.push([...points[(c * step) % points.length].vector]);
39 }
40
41 const labels = new Array(points.length).fill(0);
42
43 for (let it = 0; it < maxIter; it++) {
44 let changed = false;
45 for (let i = 0; i < points.length; i++) {
46 let best = 0;
47 let bestD = Infinity;
48 for (let c = 0; c < k; c++) {
49 const d = distSq(points[i].vector, centroids[c]);
50 if (d < bestD) {
51 bestD = d;
52 best = c;
53 }
54 }
55 if (labels[i] !== best) {
56 labels[i] = best;
57 changed = true;
58 }
59 }
60 const groups = Array.from({ length: k }, () => []);
61 for (let i = 0; i < points.length; i++) {
62 groups[labels[i]].push(points[i].vector);
63 }
64 for (let c = 0; c < k; c++) {
65 if (groups[c].length) centroids[c] = mean(groups[c]);
66 }
67 if (!changed) break;
68 }
69
70 return { labels, centroids };
71 }
File History 2 commits
sha256:65ccb454656ea5acdea0a10e559b78bcde1eb6ff753ecc2911bc99d1c3d7cadd feat(calendar): enforce agent context tiers in retrieval AP… Human minor ⚠ 1 day ago
sha256:9103f98c89257ed2b01c237cea895dabb3e85ea337dccb1161c175e4422355b6 docs: accept Calendar Events v0 spec with Phase 0 security … Human 2 days ago