bar_axis_space_saving.vg.json

{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "description": "Bar Chart with a spacing-saving y-axis",
  "background": "white",
  "padding": 5,
  "width": 200,
  "style": "cell",
  "data": [
    {
      "name": "source_0",
      "url": "data/cars.json",
      "format": {"type": "json"},
      "transform": [
        {
          "type": "aggregate",
          "groupby": ["Origin"],
          "ops": ["count"],
          "fields": [null],
          "as": ["__count"]
        }
      ]
    }
  ],
  "signals": [
    {"name": "y_step", "value": 50},
    {"name": "height", "update": "bandspace(domain('y').length, 0, 0) * y_step"}
  ],
  "marks": [
    {
      "name": "marks",
      "type": "rect",
      "style": ["bar"],
      "from": {"data": "source_0"},
      "encode": {
        "update": {
          "cornerRadiusTopRight": {"value": 2},
          "cornerRadiusBottomRight": {"value": 2},
          "fill": {"value": "#4c78a8"},
          "ariaRoleDescription": {"value": "bar"},
          "description": {
            "signal": "\"Number of Cars: \" + (format(datum[\"__count\"], \"\")) + \"; Origin: \" + (isValid(datum[\"Origin\"]) ? datum[\"Origin\"] : \"\"+datum[\"Origin\"])"
          },
          "x": {"scale": "x", "field": "__count"},
          "x2": {"scale": "x", "value": 0},
          "y": {"scale": "y", "field": "Origin", "offset": 5, "band": 0.25},
          "height": {"signal": "max(0.25, 0.5 * bandwidth('y'))"}
        }
      }
    }
  ],
  "scales": [
    {
      "name": "x",
      "type": "linear",
      "domain": {"data": "source_0", "field": "__count"},
      "range": [0, {"signal": "width"}],
      "nice": true,
      "zero": true
    },
    {
      "name": "y",
      "type": "band",
      "domain": {"data": "source_0", "field": "Origin", "sort": true},
      "range": {"step": {"signal": "y_step"}},
      "padding": 0
    }
  ],
  "axes": [
    {
      "scale": "y",
      "orient": "left",
      "bandPosition": 0,
      "grid": true,
      "gridScale": "x",
      "domain": false,
      "labels": false,
      "aria": false,
      "maxExtent": 0,
      "minExtent": 0,
      "ticks": false,
      "zindex": 0
    },
    {
      "scale": "x",
      "orient": "bottom",
      "grid": false,
      "title": "Number of Cars",
      "labelFlush": true,
      "labelOverlap": true,
      "tickCount": {"signal": "ceil(width/40)"},
      "zindex": 0
    },
    {
      "scale": "y",
      "orient": "left",
      "grid": false,
      "title": "Origin",
      "bandPosition": 0,
      "domain": false,
      "labelAlign": "left",
      "labelBaseline": "middle",
      "labelOffset": -15,
      "labelPadding": -5,
      "ticks": false,
      "titleAlign": "left",
      "titleX": 5,
      "titleY": -5,
      "titleAngle": 0,
      "zindex": 0
    }
  ]
}