probabilistic-js

A lightweight, high-performance JavaScript library for probabilistic data structures.
Designed for memory efficiency and speed, ideal for large-scale data processing.

Currently supported:
- Bloom Filter – fast membership checks
- HyperLogLog – approximate unique count (cardinality estimation)

---

Features

- 🚀 High Performance – Powered by murmurhash3js
- 💾 Memory Efficient – Uses Uint8Array
- 🎯 Configurable Accuracy – Control false positives and estimation error
- 🧠 Production Ready – Industry-standard algorithms
- 📦 Lightweight – Zero unnecessary dependencies

---

Installation

```bash
npm install probabilistic-js




//importing
const { BloomFilter, HyperLogLog, optimalParams } = require("probabilistic-js");


//BloomFilterUsage

const filter = BloomFilter.fromExpectedItems(1000, 0.01) (here 1000 is no of expected items and 0.1 false positive probability (1%) )


filter.add("apple");
filter.add("banana");

console.log(filter.contains("apple")); // true
console.log(filter.contains("grape")); // false (probably)

Manual_Config

const filter = new BloomFilter(5000, 4);


Clear_Filter

filter.clear();


//HyperLogLog

const hll = new HyperLogLog(12);

Usage

hll.add("user1");
hll.add("user2");
hll.add("user1");

console.log(hll.count()); // ≈ 2


hll.clear(); // clear hyper log













Expression binding
formatter
change the controller behaviour based on model
event bus