{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "background": "white",
  "padding": 5,
  "width": 200,
  "height": 200,
  "style": "cell",
  "data": [
    {
      "name": "source_0",
      "url": "data/cars.json",
      "format": {"type": "json", "parse": {"Year": "date"}},
      "transform": [
        {
          "field": "Year",
          "type": "timeunit",
          "units": ["year"],
          "as": ["year_Year", "year_Year_end"]
        },
        {
          "type": "aggregate",
          "groupby": ["year_Year", "Cylinders"],
          "ops": ["sum"],
          "fields": ["Weight_in_lbs"],
          "as": ["sum_Weight_in_lbs"]
        },
        {
          "type": "impute",
          "field": "sum_Weight_in_lbs",
          "groupby": ["Cylinders"],
          "key": "year_Year",
          "method": "value",
          "value": 0
        },
        {
          "type": "stack",
          "groupby": ["year_Year"],
          "field": "sum_Weight_in_lbs",
          "sort": {"field": ["Cylinders"], "order": ["descending"]},
          "as": ["sum_Weight_in_lbs_start", "sum_Weight_in_lbs_end"],
          "offset": "zero"
        }
      ]
    }
  ],
  "marks": [
    {
      "name": "pathgroup",
      "type": "group",
      "from": {
        "facet": {
          "name": "faceted_path_main",
          "data": "source_0",
          "groupby": ["Cylinders"]
        }
      },
      "encode": {
        "update": {
          "width": {"field": {"group": "width"}},
          "height": {"field": {"group": "height"}}
        }
      },
      "marks": [
        {
          "name": "marks",
          "type": "area",
          "style": ["area"],
          "sort": {"field": "datum[\"year_Year\"]"},
          "from": {"data": "faceted_path_main"},
          "encode": {
            "update": {
              "interpolate": {"value": "monotone"},
              "orient": {"value": "vertical"},
              "fill": {"scale": "color", "field": "Cylinders"},
              "description": {
                "signal": "\"Year (year): \" + (timeFormat(datum[\"year_Year\"], timeUnitSpecifier([\"year\"], {\"year-month\":\"%b %Y \",\"year-month-date\":\"%b %d, %Y \"}))) + \"; Sum of Weight_in_lbs: \" + (format(datum[\"sum_Weight_in_lbs\"], \"\")) + \"; Cylinders: \" + (isValid(datum[\"Cylinders\"]) ? datum[\"Cylinders\"] : \"\"+datum[\"Cylinders\"])"
              },
              "x": {"scale": "x", "field": "year_Year"},
              "y": {"scale": "y", "field": "sum_Weight_in_lbs_end"},
              "y2": {"scale": "y", "field": "sum_Weight_in_lbs_start"},
              "defined": {
                "signal": "isValid(datum[\"year_Year\"]) && isFinite(+datum[\"year_Year\"]) && isValid(datum[\"sum_Weight_in_lbs\"]) && isFinite(+datum[\"sum_Weight_in_lbs\"])"
              }
            }
          }
        }
      ]
    }
  ],
  "scales": [
    {
      "name": "x",
      "type": "time",
      "domain": {"data": "source_0", "field": "year_Year"},
      "range": [0, {"signal": "width"}]
    },
    {
      "name": "y",
      "type": "linear",
      "domain": {
        "data": "source_0",
        "fields": ["sum_Weight_in_lbs_start", "sum_Weight_in_lbs_end"]
      },
      "range": [{"signal": "height"}, 0],
      "nice": true,
      "zero": true
    },
    {
      "name": "color",
      "type": "ordinal",
      "domain": {"data": "source_0", "field": "Cylinders", "sort": true},
      "range": "ordinal",
      "interpolate": "hcl"
    }
  ],
  "axes": [
    {
      "scale": "x",
      "orient": "bottom",
      "gridScale": "y",
      "grid": true,
      "tickCount": {"signal": "ceil(width/40)"},
      "domain": false,
      "labels": false,
      "aria": false,
      "maxExtent": 0,
      "minExtent": 0,
      "ticks": false,
      "zindex": 0
    },
    {
      "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": "Year (year)",
      "format": {
        "signal": "timeUnitSpecifier([\"year\"], {\"year-month\":\"%b %Y \",\"year-month-date\":\"%b %d, %Y \"})"
      },
      "labelFlush": true,
      "labelOverlap": true,
      "tickCount": {"signal": "ceil(width/40)"},
      "zindex": 0
    },
    {
      "scale": "y",
      "orient": "left",
      "grid": false,
      "title": "Sum of Weight_in_lbs",
      "labelOverlap": true,
      "tickCount": {"signal": "ceil(height/40)"},
      "zindex": 0
    }
  ],
  "legends": [{"fill": "color", "symbolType": "circle", "title": "Cylinders"}]
}