Important: Synaptic 2.x is in stage of discussion now! Feel free to participate
Synaptic is a javascript neural network library for node.js and the browser, its generalized algorithm is architecture-free, so you can build and train basically any type of first order or even second order neural network architectures.
This library includes a few built-in architectures like multilayer perceptrons, multilayer long-short term memory networks (LSTM), liquid state machines or Hopfield networks, and a trainer capable of training any given network, which includes built-in training tasks/tests like solving an XOR, completing a Distracted Sequence Recall task or an Embedded Reber Grammar test, so you can easily test and compare the performance of different architectures.
The algorithm implemented by this library has been taken from Derek D. Monner's paper:
A generalized LSTM-like training algorithm for second-order recurrent neural networks
There are references to the equations in that paper commented through the source code.
####Introduction
If you have no prior knowledge about Neural Networks, you should start by reading this guide.
If you want a practical example on how to feed data to a neural network, then take a look at this article.
You may also want to take a look at this article.
####Demos
- Solve an XOR
- Discrete Sequence Recall Task
- Learn Image Filters
- Paint an Image
- Self Organizing Map
- Read from Wikipedia
The source code of these demos can be found in this branch.
####Getting started
To try out the examples, checkout the gh-pages branch.
git checkout gh-pages
##Overview
###Installation
#####In node
You can install synaptic with npm:
npm install synaptic --save
#####In the browser
You can install synaptic with bower:
bower install synaptic
Or you can simply use the CDN link, kindly provided by CDNjs
<script src="https://cdnjs.cloudflare.com/ajax/libs/synaptic/1.0.8/synaptic.js"></script>
###Usage
var synaptic = require('synaptic'); // this line is not needed in the browser var Neuron = synaptic.Neuron, Layer = synaptic.Layer, Network = synaptic.Network, Trainer = synaptic.Trainer, Architect = synaptic.Architect;
Now you can start to create networks, train them, or use built-in networks from the Architect.
###Examples
#####Perceptron
This is how you can create a simple perceptron:
.
function Perceptron(input, hidden, output) { // create the layers var inputLayer = new Layer(input); var hiddenLayer = new Layer(hidden); var outputLayer = new Layer(output); // connect the layers inputLayer.project(hiddenLayer); hiddenLayer.project(outputLayer); // set the layers this.set({ input: inputLayer, hidden: [hiddenLayer], output: outputLayer }); } // extend the prototype chain Perceptron.prototype = new Network(); Perceptron.prototype.constructor = Perceptron;
Now you can test your new network by creating a trainer and teaching the perceptron to learn an XOR
var myPerceptron = new Perceptron(2,3,1); var myTrainer = new Trainer(myPerceptron); myTrainer.XOR(); // { error: 0.004998819355993572, iterations: 21871, time: 356 } myPerceptron.activate([0,0]); // 0.0268581547421616 myPerceptron.activate([1,0]); // 0.9829673642853368 myPerceptron.activate([0,1]); // 0.9831714267395621 myPerceptron.activate([1,1]); // 0.02128894618097928
#####Long Short-Term Memory
This is how you can create a simple long short-term memory network with input gate, forget gate, output gate, and peephole connections:
function LSTM(input, blocks, output) { // create the layers var inputLayer = new Layer(input); var inputGate = new Layer(blocks); var forgetGate = new Layer(blocks); var memoryCell = new Layer(blocks); var outputGate = new Layer(blocks); var outputLayer = new Layer(output); // connections from input layer var input = inputLayer.project(memoryCell); inputLayer.project(inputGate); inputLayer.project(forgetGate); inputLayer.project(outputGate); // connections from memory cell var output = memoryCell.project(outputLayer); // self-connection var self = memoryCell.project(memoryCell); // peepholes memoryCell.project(inputGate); memoryCell.project(forgetGate); memoryCell.project(outputGate); // gates inputGate.gate(input, Layer.gateType.INPUT); forgetGate.gate(self, Layer.gateType.ONE_TO_ONE); outputGate.gate(output, Layer.gateType.OUTPUT); // input to output direct connection inputLayer.project(outputLayer); // set the layers of the neural network this.set({ input: inputLayer, hidden: [inputGate, forgetGate, memoryCell, outputGate], output: outputLayer }); } // extend the prototype chain LSTM.prototype = new Network(); LSTM.prototype.constructor = LSTM;
These are examples for explanatory purposes, the Architect already includes Multilayer Perceptrons and Multilayer LSTM network architectures.
##Contribute
Synaptic is an Open Source project that started in Buenos Aires, Argentina. Anybody in the world is welcome to contribute to the development of the project.
If you want to contribute feel free to send PR's, just make sure to run npm run test and npm run build before submiting it. This way you'll run all the test specs and build the web distribution files.
<3