sigma

Sigma.js

Sigma.js is an open-source JavaScript library aimed at visualizing graphs of thousands of nodes and edges, mainly developed by @jacomyal and @Yomguithereal.

Overview

Architecture

Since version v2, sigma.js focuses on the management of graph display: rendering, interaction... The graph model is managed in a separate library called graphology, which is packed with convenience methods to manage graph data structures, and a lot of satellite libraries to handle various graph-related problems (metrics, community detection, layout algorithms...).

Graphology website offers a list of these libraries. Most of them can help you solve problems in your sigma.js based web applications.

Rendering

Sigma.js uses WebGL to render graphs. This makes it good at rendering medium to larger graphs in web pages (thousands of nodes and edges or more). It is also possible to customize rendering, but it is harder than it would be with SVG or Canvas based solutions.

Each way to draw a node or an edge is implemented as a program. You can develop your own, or use the owns provided by sigma. You can check this example to see how to use multiple programs. Also, you can check the list of available programs here.

Installation

You can install sigma (and graphology which is required for sigma to work) in your JavaScript or TypeScript project using npm:

npm install graphology sigma

Examples

The examples folder contains a series of self-contained TypeScript projects that you can either browse and edit on CodeSandbox or install locally likewise:

git clone [e-mail]:jacomyal/sigma.js.git
cd sigma.js
npm install
cd examples
npm start --example=load-gexf-file # Change this to the desired example

List of available examples

• Fetching and displaying a graph contained in a gexf file
• Using node & edge reducers to handle interactivity
• Fetching, parsing & wrangling a CSV file to create a network map
• Handling drag and drop of nodes as well as node & edge creation on click
• Displaying arbitrary elements, such as cluster labels, synchronized with the network
• Applying different animated layout algorithms to a network
• Displaying nodes in various custom ways
• Saving the graph as a PNG image
• Use events to implement interactions

Also, a more realistic sigma.js based web application is available in the demo folder. It aims to show a real-world usecase, and is the main showcase of sigma.js website.

Website

The current website is a simple manually crafted single-page website. It is located in the website folder. It also showcases the React.js based demo available in the demo folder in an iframe. The website itself does not need any build step, though the demo does.

It has been kindly designed by Robin de Mourat from the Sciences-Po médialab team.

Development

To start a dev server that will reload the webpage when the code is updated, run:

npm run website:watch

Then, open localhost:8080 in your browser. When any file in the website directory is saved (including the demo bundle), the page will be reloaded.

Build

To simply build the demo and copy the bundle in the website folder, just run:

npm run website:all

Contributing

You can contribute by submitting issues tickets and proposing pull requests. Make sure that tests and linting pass before submitting any pull request.

You can also browse the related documentation here.