Genome Serialization

The NEAT library provides functionality to save genomes to JSON format and load them back, allowing for persistence of evolved neural networks across sessions.

Saving Genomes

toJSON

genome.toJSON() → String

Converts a genome to a JSON string representation that can be stored in a file or database.

Returns	Type	Description
jsonString	String	JSON string representation of the genome

javascript

// Save a genome to JSON
const jsonString = genome.toJSON();
console.log(jsonString);

// Write to a file (in Node.js)
const fs = require('fs');
fs.writeFileSync('best_genome.json', jsonString);

Note

The JSON structure includes the genome's ID, node genes, connection genes, fitness score, and population ID. This provides all the information needed to reconstruct the genome later.

Loading Genomes

GenomeBuilder.loadGenome

GenomeBuilder.loadGenome(jsonData, config) → Genome

Recreates a genome from its JSON representation.

Parameter	Type	Description
jsonData	String	JSON string representation of a genome
config	Object	Configuration parameters for the genome

Returns	Type	Description
genome	Genome	A reconstructed genome with the same structure and weights

javascript

// Load a genome from JSON string
const jsonString = genome.toJSON();
const newGenome = GenomeBuilder.loadGenome(jsonString, config);

// Load from a file (in Node.js)
const fs = require('fs');
const savedGenomeJson = fs.readFileSync('best_genome.json', 'utf8');
const loadedGenome = GenomeBuilder.loadGenome(savedGenomeJson, config);

Example: Saving and Loading the Best Genome

javascript

// After evolution completes, get the best genome
const bestGenome = population.getBestGenome();

// Save the best genome to JSON
const jsonString = bestGenome.toJSON();
console.log("Best genome saved, fitness:", bestGenome.fitness);

// Store in a file
const fs = require('fs');
fs.writeFileSync('best_genome.json', jsonString);

// Later, in another session, load the genome back
const savedGenomeJson = fs.readFileSync('best_genome.json', 'utf8');
const loadedGenome = GenomeBuilder.loadGenome(savedGenomeJson, config);

// Use the loaded genome for inference
const inputs = [0.5, 0.7];
loadedGenome.resetState();
const outputs = loadedGenome.propagate(inputs);
console.log("Loaded genome outputs:", outputs);