{
  //
  // ATTENTION: This code is maintained at https://en.wikipedia.org/wiki/Template:Graph:Saint_Petersburg_Metro_expansion
  //            Please do not modify it anywhere else, as it may get copied and override your changes.
  //            Suggestions can be made at https://en.wikipedia.org/wiki/Template_talk:Graph:Saint_Petersburg_Metro_expansion
  //
  //            This graph uses data from https://en.wikipedia.org/wiki/Template:Graph:Saint_Petersburg_Metro_expansion/Data-json


  "version": 2,
  "width": 800,
  "height": 400,
  "data": [
    {
      "name": "table",
      "url": "wikiraw://en.wikipedia.org/Template:Graph:Saint_Petersburg Metro expansion/Data-json",
      "format": {"type": "json"}
    },
    {
      "name": "stats",
      "source": "table",
      "transform": [
        { "type": "aggregate", "groupby": ["y"], "summarize": [{"field": "n", "ops": ["sum"]}] },
      ]
    }
  ],
  "scales": [
    {
      "name": "scale_years",
      "type": "linear",
      "domain": {"data": "table", "field": "y"},
      "range": "width",
      "zero": false
    },
    {
      "name": "scale_stations",
      "type": "linear",
      "domain": {"data": "stats", "field": "sum_n"},
      "range": "height"
    },
    {
      "name": "scale_colour",
      "type": "ordinal",
      "domain": [1,2,3,4,5,6],
      "range": [ "#EF161E", "#0000ff", "#008000", "#ffa500", "#540099", "#964b00"]
    }
  ],
  "axes": [
    {
      "type": "x",
      "scale": "scale_years",
      "title": "Year",
      "values": [1955,1965,1975,1985,1995,2005,2015,2025],
      "subdivide": 8,
      "tickSizeMinor": 4,
      "tickSizeEnd": 0,
      "format": "d"
    },
    {
      "type": "y",
      "scale": "scale_stations",
      "title": "Number of stations"
    },
    {
      "type": "y",
      "scale": "scale_stations",
      "title": "Number of stations",
      "orient": "right"
    }
  ],
  "marks": [
    {
      "type": "group",
      "from": {
        "data": "table",
        "transform": [
          {"type": "stack","groupby": "y","sortby":"l", "field": "n"},
          {"type": "facet","groupby": ["l"]}
        ]
      },
      "marks": [
        {
          "type": "area",
          "properties": {
            "enter": {
              "interpolate": {"value": "linear"},
              "x": {"scale": "scale_years","field": "y"},
              "y": {"scale": "scale_stations","field": "layout_start"},
              "y2": {"scale": "scale_stations","field": "layout_end"},
              "fill": {"scale": "scale_colour","field": "l"}
            }
          }
        }
      ]
    }
  ]
}