{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "description": "A error bar plot showing mean, min, and max in the US population distribution of age groups in 2000.",
  "background": "white",
  "padding": 5,
  "height": 200,
  "style": "cell",
  "data": [
    {
      "name": "source_0",
      "url": "data/population.json",
      "format": {"type": "json", "parse": {"people": "number"}},
      "transform": [
        {"type": "filter", "expr": "datum.year == 2000"},
        {
          "type": "aggregate",
          "groupby": ["age"],
          "ops": ["mean", "min", "max"],
          "fields": ["people", "people", "people"],
          "as": ["mean_people", "min_people", "max_people"]
        }
      ]
    },
    {
      "name": "data_0",
      "source": "source_0",
      "transform": [
        {
          "type": "filter",
          "expr": "isValid(datum[\"mean_people\"]) && isFinite(+datum[\"mean_people\"])"
        }
      ]
    },
    {
      "name": "data_1",
      "source": "source_0",
      "transform": [
        {
          "type": "filter",
          "expr": "isValid(datum[\"min_people\"]) && isFinite(+datum[\"min_people\"])"
        }
      ]
    },
    {
      "name": "data_2",
      "source": "source_0",
      "transform": [
        {
          "type": "filter",
          "expr": "isValid(datum[\"max_people\"]) && isFinite(+datum[\"max_people\"])"
        }
      ]
    }
  ],
  "signals": [
    {"name": "x_step", "value": 20},
    {"name": "width", "update": "bandspace(domain('x').length, 0, 0) * x_step"}
  ],
  "marks": [
    {
      "name": "layer_0_marks",
      "type": "rule",
      "style": ["rule"],
      "from": {"data": "data_1"},
      "encode": {
        "update": {
          "stroke": {"value": "black"},
          "description": {
            "signal": "\"age: \" + (isValid(datum[\"age\"]) ? datum[\"age\"] : \"\"+datum[\"age\"]) + \"; population: \" + (format(datum[\"min_people\"], \"\")) + \"; Max of people: \" + (format(datum[\"max_people\"], \"\"))"
          },
          "x": {"scale": "x", "field": "age", "band": 0.5},
          "y": {"scale": "y", "field": "min_people"},
          "y2": {"scale": "y", "field": "max_people"}
        }
      }
    },
    {
      "name": "layer_1_marks",
      "type": "rect",
      "style": ["tick"],
      "from": {"data": "data_1"},
      "encode": {
        "update": {
          "fill": {"value": "#4c78a8"},
          "ariaRoleDescription": {"value": "tick"},
          "description": {
            "signal": "\"age: \" + (isValid(datum[\"age\"]) ? datum[\"age\"] : \"\"+datum[\"age\"]) + \"; population: \" + (format(datum[\"min_people\"], \"\"))"
          },
          "xc": {"scale": "x", "field": "age", "band": 0.5},
          "yc": {"scale": "y", "field": "min_people"},
          "width": {"value": 5},
          "height": {"value": 1}
        }
      }
    },
    {
      "name": "layer_2_marks",
      "type": "rect",
      "style": ["tick"],
      "from": {"data": "data_2"},
      "encode": {
        "update": {
          "fill": {"value": "#4c78a8"},
          "ariaRoleDescription": {"value": "tick"},
          "description": {
            "signal": "\"age: \" + (isValid(datum[\"age\"]) ? datum[\"age\"] : \"\"+datum[\"age\"]) + \"; population: \" + (format(datum[\"max_people\"], \"\"))"
          },
          "xc": {"scale": "x", "field": "age", "band": 0.5},
          "yc": {"scale": "y", "field": "max_people"},
          "width": {"value": 5},
          "height": {"value": 1}
        }
      }
    },
    {
      "name": "layer_3_marks",
      "type": "symbol",
      "style": ["point"],
      "from": {"data": "data_0"},
      "encode": {
        "update": {
          "fill": {"value": "transparent"},
          "stroke": {"value": "#4c78a8"},
          "ariaRoleDescription": {"value": "point"},
          "description": {
            "signal": "\"age: \" + (isValid(datum[\"age\"]) ? datum[\"age\"] : \"\"+datum[\"age\"]) + \"; population: \" + (format(datum[\"mean_people\"], \"\"))"
          },
          "x": {"scale": "x", "field": "age", "band": 0.5},
          "y": {"scale": "y", "field": "mean_people"},
          "size": {"value": 2}
        }
      }
    }
  ],
  "scales": [
    {
      "name": "x",
      "type": "band",
      "domain": {
        "fields": [
          {"data": "data_1", "field": "age"},
          {"data": "data_2", "field": "age"},
          {"data": "data_0", "field": "age"}
        ],
        "sort": true
      },
      "range": {"step": {"signal": "x_step"}},
      "paddingInner": 0,
      "paddingOuter": 0
    },
    {
      "name": "y",
      "type": "linear",
      "domain": {
        "fields": [
          {"data": "data_1", "field": "min_people"},
          {"data": "data_1", "field": "max_people"},
          {"data": "data_2", "field": "max_people"},
          {"data": "data_0", "field": "mean_people"}
        ]
      },
      "range": [{"signal": "height"}, 0],
      "nice": true,
      "zero": true
    }
  ],
  "axes": [
    {
      "scale": "y",
      "orient": "left",
      "gridScale": "x",
      "grid": true,
      "tickCount": {"signal": "ceil(height/40)"},
      "domain": false,
      "labels": false,
      "aria": false,
      "maxExtent": 0,
      "minExtent": 0,
      "ticks": false,
      "zindex": 0
    },
    {
      "scale": "x",
      "orient": "bottom",
      "grid": false,
      "title": "age",
      "labelAlign": "right",
      "labelAngle": 270,
      "labelBaseline": "middle",
      "zindex": 0
    },
    {
      "scale": "y",
      "orient": "left",
      "grid": false,
      "title": "population",
      "labelOverlap": true,
      "tickCount": {"signal": "ceil(height/40)"},
      "zindex": 0
    }
  ]
}