@graphty/layout/src/generators/random.ts

graph layout algorithms based on networkx

/**
 * Random graph generation function
 */

import { Graph, Node, Edge } from '../types';

/**
 * Create a random graph with n nodes and given edge probability
 * @param n - Number of nodes
 * @param p - Probability of edge between any two nodes (0-1)
 * @param seed - Random seed for reproducibility
 * @returns Graph object with random edges
 */
export function randomGraph(n: number, p: number, seed?: number): Graph {
  const nodes: Node[] = Array.from({ length: n }, (_, i) => i);
  const edges: Edge[] = [];
  
  // Simple deterministic pseudo-random if seed provided
  let currentSeed = seed;
  let random = seed !== undefined 
    ? () => {
        currentSeed = (currentSeed! * 9301 + 49297) % 233280;
        return currentSeed / 233280;
      }
    : Math.random;
  
  for (let i = 0; i < n; i++) {
    for (let j = i + 1; j < n; j++) {
      if (random() < p) {
        edges.push([i, j]);
      }
    }
  }
  
  return {
    nodes: () => nodes,
    edges: () => edges
  };
}