bar_grouped_errorbar.vg.json

{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "description": "A vertical box plot showing median, min, and max body mass of penguins.",
  "background": "white",
  "padding": 5,
  "height": 200,
  "style": "cell",
  "data": [
    {
      "name": "source_0",
      "url": "data/cars.json",
      "format": {"type": "json"},
      "transform": [
        {
          "type": "aggregate",
          "groupby": ["Cylinders", "Origin"],
          "ops": ["stderr", "mean", "mean"],
          "fields": ["Acceleration", "Acceleration", "Acceleration"],
          "as": [
            "extent_Acceleration",
            "center_Acceleration",
            "mean_Acceleration"
          ]
        }
      ]
    },
    {
      "name": "data_0",
      "source": "source_0",
      "transform": [
        {
          "type": "formula",
          "expr": "datum[\"center_Acceleration\"] + datum[\"extent_Acceleration\"]",
          "as": "upper_Acceleration"
        },
        {
          "type": "formula",
          "expr": "datum[\"center_Acceleration\"] - datum[\"extent_Acceleration\"]",
          "as": "lower_Acceleration"
        },
        {
          "type": "filter",
          "expr": "isValid(datum[\"lower_Acceleration\"]) && isFinite(+datum[\"lower_Acceleration\"])"
        }
      ]
    },
    {
      "name": "data_1",
      "source": "source_0",
      "transform": [
        {
          "type": "filter",
          "expr": "isValid(datum[\"mean_Acceleration\"]) && isFinite(+datum[\"mean_Acceleration\"])"
        }
      ]
    }
  ],
  "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": "layer_0_marks",
      "type": "rect",
      "style": ["bar"],
      "from": {"data": "data_1"},
      "encode": {
        "update": {
          "fill": {"scale": "color", "field": "Origin"},
          "ariaRoleDescription": {"value": "bar"},
          "description": {
            "signal": "\"Cylinders: \" + (isValid(datum[\"Cylinders\"]) ? datum[\"Cylinders\"] : \"\"+datum[\"Cylinders\"]) + \"; Mean of Acceleration: \" + (format(datum[\"mean_Acceleration\"], \"\")) + \"; Origin: \" + (isValid(datum[\"Origin\"]) ? datum[\"Origin\"] : \"\"+datum[\"Origin\"])"
          },
          "x": {
            "scale": "x",
            "field": "Cylinders",
            "offset": {"scale": "xOffset", "field": "Origin"}
          },
          "width": {"signal": "max(0.25, bandwidth('xOffset'))"},
          "y": {"scale": "y", "field": "mean_Acceleration"},
          "y2": {"scale": "y", "value": 0}
        }
      }
    },
    {
      "name": "layer_1_marks",
      "type": "rule",
      "style": ["rule", "errorbar-rule"],
      "from": {"data": "data_0"},
      "encode": {
        "update": {
          "ariaRoleDescription": {"value": "errorbar"},
          "stroke": {"value": "black"},
          "tooltip": {
            "signal": "{\"Mean of Acceleration\": format(datum[\"center_Acceleration\"], \"\"), \"Mean + stderr of Acceleration\": format(datum[\"upper_Acceleration\"], \"\"), \"Mean - stderr of Acceleration\": format(datum[\"lower_Acceleration\"], \"\"), \"Cylinders\": isValid(datum[\"Cylinders\"]) ? datum[\"Cylinders\"] : \"\"+datum[\"Cylinders\"], \"Origin\": isValid(datum[\"Origin\"]) ? datum[\"Origin\"] : \"\"+datum[\"Origin\"]}"
          },
          "description": {
            "signal": "\"Cylinders: \" + (isValid(datum[\"Cylinders\"]) ? datum[\"Cylinders\"] : \"\"+datum[\"Cylinders\"]) + \"; Acceleration: \" + (format(datum[\"lower_Acceleration\"], \"\")) + \"; upper_Acceleration: \" + (format(datum[\"upper_Acceleration\"], \"\")) + \"; Origin: \" + (isValid(datum[\"Origin\"]) ? datum[\"Origin\"] : \"\"+datum[\"Origin\"]) + \"; Mean of Acceleration: \" + (format(datum[\"center_Acceleration\"], \"\")) + \"; Mean + stderr of Acceleration: \" + (format(datum[\"upper_Acceleration\"], \"\")) + \"; Mean - stderr of Acceleration: \" + (format(datum[\"lower_Acceleration\"], \"\"))"
          },
          "x": {
            "scale": "x",
            "field": "Cylinders",
            "offset": {"scale": "xOffset", "field": "Origin", "band": 0.5}
          },
          "y": {"scale": "y", "field": "lower_Acceleration"},
          "y2": {"scale": "y", "field": "upper_Acceleration"}
        }
      }
    }
  ],
  "scales": [
    {
      "name": "x",
      "type": "band",
      "domain": {
        "fields": [
          {"data": "data_1", "field": "Cylinders"},
          {"data": "data_0", "field": "Cylinders"}
        ],
        "sort": true
      },
      "range": {"step": {"signal": "x_step"}},
      "paddingInner": 0.2,
      "paddingOuter": 0.2
    },
    {
      "name": "y",
      "type": "linear",
      "domain": {
        "fields": [
          {"data": "data_1", "field": "mean_Acceleration"},
          {"data": "data_0", "field": "lower_Acceleration"},
          {"data": "data_0", "field": "upper_Acceleration"}
        ]
      },
      "range": [{"signal": "height"}, 0],
      "nice": true,
      "zero": true
    },
    {
      "name": "xOffset",
      "type": "band",
      "domain": {
        "fields": [
          {"data": "data_1", "field": "Origin"},
          {"data": "data_0", "field": "Origin"}
        ],
        "sort": true
      },
      "range": {"step": 20}
    },
    {
      "name": "color",
      "type": "ordinal",
      "domain": {"data": "data_1", "field": "Origin", "sort": true},
      "range": "category"
    }
  ],
  "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": "Acceleration",
      "labelOverlap": true,
      "tickCount": {"signal": "ceil(height/40)"},
      "zindex": 0
    }
  ],
  "legends": [{"fill": "color", "symbolType": "square", "title": "Origin"}]
}