sigma.layout.forceAtlas2

Algorithm by Mathieu Jacomy.

Plugin by Guillaume Plique.

This plugin implements ForceAtlas2, a force-directed layout algorithm.

For optimization purposes, the algorithm’s computations are delegated to a web worker.

Methods

sigma.startForceAtlas2

Starts or unpauses the layout. It is possible to pass a configuration if this is the first time you start the layout.

sigmaInstance.startForceAtlas2(config);

sigma.stopForceAtlas2

Pauses the layout.

sigmaInstance.stopForceAtlas2();

sigma.configForceAtlas2

Changes the layout’s configuration.

sigmaInstance.configForceAtlas2(config);

sigma.killForceAtlas2

Completely stops the layout and terminates the assiociated worker. You can still restart it later, but a new worker will have to initialize.

sigmaInstance.killForceAtlas2();

sigma.isForceAtlas2Running

Returns whether ForceAtlas2 is running.

sigmaInstance.isForceAtlas2Running();

Configuration

Algorithm configuration

  • linLogMode boolean false: switch ForceAtlas’ model from lin-lin to lin-log (tribute to Andreas Noack). Makes clusters more tight.
  • outboundAttractionDistribution boolean false
  • adjustSizes boolean false
  • edgeWeightInfluence number 0: how much influence you give to the edges weight. 0 is “no influence” and 1 is “normal”.
  • scalingRatio number 1: how much repulsion you want. More makes a more sparse graph.
  • strongGravityMode boolean false
  • gravity number 1: attracts nodes to the center. Prevents islands from drifting away.
  • barnesHutOptimize boolean true: should we use the algorithm’s Barnes-Hut to improve repulsion’s scalability (O(n²) to O(nlog(n)))? This is useful for large graph but harmful to small ones.
  • barnesHutTheta number 0.5
  • slowDown number 1
  • startingIterations integer 1: number of iterations to be run before the first render.
  • iterationsPerRender integer 1: number of iterations to be run before each render.

Supervisor configuration

  • worker boolean true: should the layout use a web worker?
  • workerUrl string : path to the worker file if needed because your browser does not support blob workers.

Notes

  1. The layout won’t stop by itself, so if you want it to stop, you will have to trigger it explicitly.