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javascriptgraph-theorycytoscape.jscytoscape

How to make a weighted graph in Cytoscape.js?

Im new to cytoscape, I have read the docs but can't find something that helps. Is there a way to make something like this (a weighted graph) in Cytoscape.js?:

enter image description here

I just need to know how to display the weight of the edge.

So far I have this:

elements: [
  // list of graph elements to start with
  {
    // node a
    data: { id: "a" },
  },
  {
    // node b
    data: { id: "b" },
  },
  {
    // edge ab
    data: { id: "ab", weight: 3, source: "a", target: "b" },
  },
],

But adding a weight to the edge doesn't display the weight in the graph: enter image description here

Solution

  • You can use 'label': 'data(weight)' in your css for the edge to show the weight property as a label of the edge. You can also adjust styling of this label as detailed here. I applied two of them (text-margin-y and text-orientation) in the below sample.

    var cy = window.cy = cytoscape({
  container: document.getElementById('cy'),
  layout: {name: 'grid', rows: 2},
  style: [{
      selector: 'node',
      css: {
        'content': 'data(id)',
        'text-valign': 'center',
        'text-halign': 'center'
      }
    },
    {
      selector: 'edge',
      css: {
        'label': 'data(weight)',
        'text-margin-y': 15,
        'text-rotation': 'autorotate'
      }
    }
  ],
  elements: {
    nodes: [{
        data: {
          id: 'n0'          
        }
      },
      {
        data: {
          id: 'n1'
        }
      },
      {
        data: {
          id: 'n2'
        }
      },
      {
        data: {
          id: 'n3'
        }
      }
    ],
    edges: [{
        data: {
          id: 'n0n1',
          source: 'n0',
          target: 'n1',
          weight: 3
        }
      },
      {
        data: {
          id: 'n1n2',        
          source: 'n1',
          target: 'n2',
          weight: 5
        }
      },
      {
        data: {
          id: 'n2n3',        
          source: 'n2',
          target: 'n3',
          weight: 7
        }
      }
    ]
  }
});
    body {
  font: 14px helvetica neue, helvetica, arial, sans-serif;
}

#cy {
  height: 95%;
  width: 95%;
  left: 0;
  top: 0;
  position: absolute;
}
    <html>

<head>
  <meta charset=utf-8 />
  <meta name="viewport" content="user-scalable=no, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, minimal-ui">
  <script src="https://unpkg.com/cytoscape@3.10.0/dist/cytoscape.min.js">
  </script>
</head>

<body>
  <div id="cy"></div>
</body>

</html>