ratio-selector

A lightweight JavaScript utility for weighted random selection based on ratios.

Features

• 🎯 Weighted random selection based on probability ratios
• 🎲 Precise probability distribution
• 💪 Type safe with TypeScript support
• 🧪 Well tested with comprehensive test cases

Installation

yarn add @jswork/ratio-selector

Usage

import ratioSelector from '@jswork/ratio-selector';

// Basic usage - items with probability ratios
const items = [
  { name: 'A', value: 0.5 }, // 50% chance
  { name: 'B', value: 0.3 }, // 30% chance
  { name: 'C', value: 0.2 }  // 20% chance
];

const result = ratioSelector(items);
// Returns: 'A' or 'B' or 'C' based on their probabilities

// Example: Reward distribution
const rewards = [
  { name: 'Common', value: 0.7 },
  { name: 'Rare', value: 0.25 },
  { name: 'Epic', value: 0.05 }
];

const reward = ratioSelector(rewards);
// Returns a reward type based on rarity

Notes

• The sum of all values must be approximately 1
• Each item must have a name (string) and value (number) property
• Values represent probability ratios (e.g., 0.3 = 30% chance)

License

Code released under the MIT license.