jrtechs-NodeJSBlog/blogContent/projects/steam/src/plugins/sigma.layout.noverlap

sigma.layout.noverlap

Plugin developed by Andrew Pitts and published under the MIT license. Original algorithm by Mathieu Jacomy and ported to sigma.js with permission.

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This plugin runs an algorithm which distributes nodes in the network, ensuring that they do not overlap and providing a margin where specified.

Methods

configure

Changes the layout's configuration.

var listener = s.configNoverlap(config);

start

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

s.startNoverlap();

isRunning

Returns whether the layout is running.

s.isNoverlapRunning();

Configuration

• nodes: array: the subset of nodes to apply the layout.

Algorithm configuration

• nodeMargin: number 5.0: The additional minimum space to apply around each and every node.
• scaleNodes: number 1.2: A multiplier to apply to nodes such that larger nodes will have more space around them if this multiplier is greater than zero.
• gridSize: integer 20: The number of rows and columns to use when dividing the nodes up into cells which the algorithm is applied to. Use more rows and columns for larger graphs for a more efficient algorithm.
• permittedExpansion number 1.1: At every step, this is the maximum ratio to apply to the bounding box, i.e. the maximum by which the network is permitted to expand.
• rendererIndex integer 0: The index of the renderer to use to compute overlap and collisions of the nodes.
• speed number 2: A larger value increases the speed with which the algorithm will convergence at the cost of precision.
• maxIterations number 500: The maximum number of iterations to run the algorithm for before stopping it.

Easing configuration

• easing string: if specified, ease the transition between nodes positions if background is true. The duration is specified by the Sigma settings animationsTime. See sigma.utils.easing for available values.
• duration number: duration of the transition for the easing method. Default value is Sigma setting animationsTime.

Events

The plugin dispatches the following events:

• start: on layout start.
• interpolate: at the beginning of the layout animation if an easing function is specified and the layout is ran on background.
• stop: on layout stop, will be dispatched after interpolate.

Example:

s = new sigma({
  graph: g,
  container: 'graph-container'
});

var config = {
  nodeMargin: 3.0,
  scaleNodes: 1.3
};

// Configure the algorithm
var listener = s.configNoverlap(config);

// Bind all events:
listener.bind('start stop interpolate', function(event) {
  console.log(event.type);
});

// Start the algorithm:
s.startNoverlap();