https://github.com/patelvivekdev/fast-bm25
BM25 (Okapi BM25) implementation in TypeScript with field boosting and parallel processing support.
https://github.com/patelvivekdev/fast-bm25
bm25 bm25-okapi fast-bm25
Last synced: 3 months ago
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BM25 (Okapi BM25) implementation in TypeScript with field boosting and parallel processing support.
- Host: GitHub
- URL: https://github.com/patelvivekdev/fast-bm25
- Owner: patelvivekdev
- License: mit
- Created: 2024-11-17T09:18:31.000Z (11 months ago)
- Default Branch: main
- Last Pushed: 2025-07-10T21:41:01.000Z (3 months ago)
- Last Synced: 2025-07-13T08:52:22.221Z (3 months ago)
- Topics: bm25, bm25-okapi, fast-bm25
- Language: TypeScript
- Homepage: https://www.npmjs.com/package/fast-bm25
- Size: 288 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE.md
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README
# fast-bm25
A high-performance BM25 (Okapi BM25) implementation in TypeScript with field boosting and parallel processing support.
## Features
- Fast BM25 ranking algorithm implementation
- Field boosting support
- Parallel document processing
- Customizable tokenization
- Stop words filtering
- Minimum token length filtering
- Optional stemming
## Installation
```bash
npm install fast-bm25
# or
yarn add fast-bm25
```
## Usage
### Basic Usage
```typescript
import { BM25 } from 'fast-bm25';
// Sample documents for demonstration
const docs = [
{ title: 'The quick brown fox', content: 'jumps over the lazy dog' },
{ title: 'The lazy brown dog', content: 'sleeps all day long' },
{ title: 'Quick fox', content: 'quick brown jumping' },
];
// Create a new BM25 instance
const bm25 = new BM25(docs);
// Query example
const query = 'brown fox';
// Get search results
const results = bm25.search(query, 2);
console.log(results);
// [
// {
// index: 2,
// score: 0.6666956543922424,
// }, {
// index: 0,
// score: 0.5762394666671753,
// }
// ]
```
### Adding Documents
```typescript
const bm25 = new BM25();
// Add documents
bm25.addDocument({ title: 'Document title', content: 'Document content' });
// Add multiple documents
bm25.addDocuments([
{ title: 'Document 1', content: 'Content 1' },
{ title: 'Document 2', content: 'Content 2' },
]);
// Add documents in parallel
const largeDocs = [
/* ... lots of documents ... */
];
await bm25.addDocumentsParallel(largeDocs);
```
### Field Boosting
```typescript
// Initialize with field boosts
const bm25WithBoosts = new BM25(docs, {
fieldBoosts: {
title: 2.0, // Title field has 2x importance
content: 1.0,
},
});
```
### Custom Options
```typescript
const customBM25 = new BM25(docs, {
k1: 1.5, // Term frequency saturation parameter
b: 0.75, // Length normalization factor
minLength: 2, // Minimum token length
stopWords: new Set(['the', 'a', 'is']), // Custom stop words
stemming: true, // Enable word stemming
});
```