Vega spec from Thu May 04 2023

spec.json

{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "description": "A node-link diagram with force-directed layout, depicting character co-occurrence in the novel Les Misérables.",
  "width": 700,
  "height": 500,
  "padding": 0,
  "autosize": "none",
  "signals": [
    {"name": "cx", "update": "width / 2"},
    {"name": "cy", "update": "height / 2"},
    {
      "name": "nodeRadius",
      "value": 8,
      "bind": {"input": "range", "min": 1, "max": 50, "step": 1}
    },
    {
      "name": "nodeCharge",
      "value": -30,
      "bind": {"input": "range", "min": -100, "max": 10, "step": 1}
    },
    {
      "name": "linkDistance",
      "value": 30,
      "bind": {"input": "range", "min": 5, "max": 100, "step": 1}
    },
    {"name": "static", "value": true, "bind": {"input": "checkbox"}}
  ],
  "data": [
    {
      "name": "node-data",
      "url": "data/miserables.json",
      "format": {"type": "json", "property": "nodes"}
    },
    {
      "name": "link-data",
      "url": "data/miserables.json",
      "format": {"type": "json", "property": "links"}
    }
  ],
  "scales": [
    {
      "name": "color",
      "type": "ordinal",
      "domain": {"data": "node-data", "field": "group"},
      "range": {"scheme": "category20c"}
    }
  ],
  "marks": [
    {
      "name": "nodes",
      "type": "symbol",
      "zindex": 1,
      "from": {"data": "node-data"},
      "encode": {
        "enter": {
          "fill": {"scale": "color", "field": "group"},
          "stroke": {"value": "white"}
        },
        "update": {
          "size": {"signal": "2 * nodeRadius * nodeRadius"},
          "cursor": {"value": "pointer"}
        }
      },
      "transform": [
        {
          "type": "force",
          "iterations": 300,
          "static": {"signal": "static"},
          "signal": "force",
          "forces": [
            {"force": "center", "x": {"signal": "cx"}, "y": {"signal": "cy"}},
            {"force": "collide", "radius": {"signal": "nodeRadius"}},
            {"force": "nbody", "strength": {"signal": "nodeCharge"}},
            {
              "force": "link",
              "links": "link-data",
              "distance": {"signal": "linkDistance"}
            }
          ]
        }
      ]
    },
    {
      "type": "path",
      "from": {"data": "link-data"},
      "interactive": false,
      "encode": {
        "update": {"stroke": {"value": "#ccc"}, "strokeWidth": {"value": 0.5}}
      },
      "transform": [
        {
          "type": "linkpath",
          "require": {"signal": "force"},
          "shape": "line",
          "sourceX": "datum.source.x",
          "sourceY": "datum.source.y",
          "targetX": "datum.target.x",
          "targetY": "datum.target.y"
        }
      ]
    }
  ]
}