ngraph.todot

Save ngraph.graph to dot format.

usage

// Let's say we have a graph with two edges:
var graph = require('ngraph.graph')();
graph.addLink(1, 2);
graph.addLink(2, 3);


// Now save it to dot format:
var toDot = require('ngraph.todot');
var dotContent = toDot(graph);

This will set dotContent to a string with a graph, described in dot format:

digraph G {
1 -> 2
2 -> 3
}

What to do with this? dot is very well supported format by multiple graph analysis software (e.g. gephi, graphviz).

You can easily transfer ngraph.graph to your favorite platform!

To read it back to ngraph.graph, use ngraph.fromdot module:

var fromDot = require('ngraph.fromdot');
var newGraph = fromDot(dotContent);

Now newGraph is an instance of ngraph.graph

Attributes

The library will store attributes of nodes/edges, with a few limitations

1. Attribute must be an object and not a primitive type
2. Composite nested objects are JSON.stringified.

var graph = require('ngraph.graph')();
graph.addNode(1, { name: 'ngraph' });
graph.addLink(1, 2, { version: '42' });


// Now save it to dot format:
var toDot = require('ngraph.todot');
var dotContent = toDot(graph);

// you can parse it back:
var fromDot = require('ngraph.fromdot');
var restored = fromDot(dotContent);
// and expect attributes to be present:

restored.getNode(1).data.name === 'ngraph'
restored.getLink(1, 2).data.version === '42'

Streaming

By default, when you toDot(graph) the output is buffered into an array, and flushed at the end. This may not be feasible for huge graphs, since it takes extra memory.

For this uses case ngraph.todot exposes a low level method write(graph, writer) which allows your code to own how actual output is stored/processed.

For example:

var graph = require('ngraph.graph')();
graph.addLink(1, 2);
graph.addLink(2, 3);

var toDot = require('ngraph.todot');

toDot.write(graph, function customWriter(line) {
  console.log(line);
});

This will print dot file on the console without using extra memory:

digraph G {
1 -> 2
2 -> 3
}

install

With npm do:

npm install ngraph.todot

license

MIT