vecstore-js/dist/search/cosine.js

A pluggable, browser-native vector database using IndexedDB with support for HNSW and local embeddings.

export const cosineSimilarity = (a, b) => {
    if (a.length === 0 || b.length === 0 || a.length !== b.length)
        return 0;
    const dot = a.reduce((sum, val, i) => sum + val * b[i], 0);
    const magnitudeA = Math.sqrt(a.reduce((sum, val) => sum + val * val, 0));
    const magnitudeB = Math.sqrt(b.reduce((sum, val) => sum + val * val, 0));
    if (magnitudeA === 0 || magnitudeB === 0)
        return 0;
    return dot / (magnitudeA * magnitudeB);
};
export class CosineSearchAlgorithm {
    async search(queryVector, documents, topK) {
        const scored = documents.map((doc) => ({
            ...doc,
            score: cosineSimilarity(queryVector, doc.vector)
        }));
        return scored
            .sort((a, b) => b.score - a.score)
            .slice(0, topK);
    }
}