{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "background": "white",
  "padding": 5,
  "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": ["Cylinders", "Origin", "year_Year"],
          "ops": ["sum"],
          "fields": ["Weight_in_lbs"],
          "as": ["sum_Weight_in_lbs"]
        },
        {
          "type": "stack",
          "groupby": ["Cylinders", "Origin"],
          "field": "sum_Weight_in_lbs",
          "sort": {"field": ["year_Year"], "order": ["descending"]},
          "as": ["sum_Weight_in_lbs_start", "sum_Weight_in_lbs_end"],
          "offset": "zero"
        },
        {
          "type": "filter",
          "expr": "isValid(datum[\"sum_Weight_in_lbs\"]) && isFinite(+datum[\"sum_Weight_in_lbs\"])"
        }
      ]
    }
  ],
  "signals": [
    {
      "name": "x_step",
      "update": "20 * bandspace(domain('xOffset').length, 0, 0) / (1-0.2)"
    },
    {
      "name": "width",
      "update": "bandspace(domain('x').length, 0.2, 0.2) * x_step"
    }
  ],
  "marks": [
    {
      "name": "marks",
      "type": "rect",
      "style": ["bar"],
      "from": {"data": "source_0"},
      "encode": {
        "update": {
          "fill": {"scale": "color", "field": "year_Year"},
          "ariaRoleDescription": {"value": "bar"},
          "description": {
            "signal": "\"Cylinders: \" + (isValid(datum[\"Cylinders\"]) ? datum[\"Cylinders\"] : \"\"+datum[\"Cylinders\"]) + \"; Sum of Weight_in_lbs: \" + (format(datum[\"sum_Weight_in_lbs\"], \"\")) + \"; Origin: \" + (isValid(datum[\"Origin\"]) ? datum[\"Origin\"] : \"\"+datum[\"Origin\"]) + \"; Year (year): \" + (timeFormat(datum[\"year_Year\"], timeUnitSpecifier([\"year\"], {\"year-month\":\"%b %Y \",\"year-month-date\":\"%b %d, %Y \"})))"
          },
          "x": {
            "scale": "x",
            "field": "Cylinders",
            "offset": {"scale": "xOffset", "field": "Origin"}
          },
          "width": {"scale": "xOffset", "band": 1},
          "y": {"scale": "y", "field": "sum_Weight_in_lbs_end"},
          "y2": {"scale": "y", "field": "sum_Weight_in_lbs_start"}
        }
      }
    }
  ],
  "scales": [
    {
      "name": "x",
      "type": "band",
      "domain": {"data": "source_0", "field": "Cylinders", "sort": true},
      "range": {"step": {"signal": "x_step"}},
      "paddingInner": 0.2,
      "paddingOuter": 0.2
    },
    {
      "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": "xOffset",
      "type": "band",
      "domain": {"data": "source_0", "field": "Origin", "sort": true},
      "range": {"step": 20}
    },
    {
      "name": "color",
      "type": "ordinal",
      "domain": {"data": "source_0", "field": "year_Year", "sort": true},
      "range": {"scheme": "category20"}
    }
  ],
  "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": "Cylinders",
      "labelAlign": "right",
      "labelAngle": 270,
      "labelBaseline": "middle",
      "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",
      "format": {
        "signal": "timeUnitSpecifier([\"year\"], {\"year-month\":\"%b %Y \",\"year-month-date\":\"%b %d, %Y \"})"
      },
      "formatType": "time",
      "symbolType": "square",
      "title": "Year (year)"
    }
  ]
}