{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "description": "Cars from Japan compared to all cars. Demonstrates independent legends in layers.",
  "background": "white",
  "padding": 5,
  "width": 200,
  "height": 200,
  "style": "cell",
  "data": [
    {
      "name": "source_0",
      "url": "data/cars.json",
      "format": {"type": "json"},
      "transform": [
        {
          "type": "extent",
          "field": "Acceleration",
          "signal": "layer_1_bin_maxbins_10_Acceleration_extent"
        },
        {
          "type": "bin",
          "field": "Acceleration",
          "as": [
            "bin_maxbins_10_Acceleration",
            "bin_maxbins_10_Acceleration_end"
          ],
          "signal": "layer_1_bin_maxbins_10_Acceleration_bins",
          "extent": {"signal": "layer_1_bin_maxbins_10_Acceleration_extent"},
          "maxbins": 10
        },
        {
          "type": "extent",
          "field": "Horsepower",
          "signal": "layer_1_bin_maxbins_10_Horsepower_extent"
        },
        {
          "type": "bin",
          "field": "Horsepower",
          "as": ["bin_maxbins_10_Horsepower", "bin_maxbins_10_Horsepower_end"],
          "signal": "layer_1_bin_maxbins_10_Horsepower_bins",
          "extent": {"signal": "layer_1_bin_maxbins_10_Horsepower_extent"},
          "maxbins": 10
        }
      ]
    },
    {
      "name": "data_0",
      "source": "source_0",
      "transform": [
        {"type": "filter", "expr": "datum.Origin === 'Japan'"},
        {
          "type": "aggregate",
          "groupby": [
            "bin_maxbins_10_Acceleration",
            "bin_maxbins_10_Acceleration_end",
            "bin_maxbins_10_Horsepower",
            "bin_maxbins_10_Horsepower_end"
          ],
          "ops": ["count"],
          "fields": [null],
          "as": ["__count"]
        },
        {
          "type": "filter",
          "expr": "isValid(datum[\"bin_maxbins_10_Acceleration\"]) && isFinite(+datum[\"bin_maxbins_10_Acceleration\"]) && isValid(datum[\"bin_maxbins_10_Horsepower\"]) && isFinite(+datum[\"bin_maxbins_10_Horsepower\"])"
        }
      ]
    },
    {
      "name": "data_1",
      "source": "source_0",
      "transform": [
        {
          "type": "aggregate",
          "groupby": [
            "bin_maxbins_10_Acceleration",
            "bin_maxbins_10_Acceleration_end",
            "bin_maxbins_10_Horsepower",
            "bin_maxbins_10_Horsepower_end"
          ],
          "ops": ["count"],
          "fields": [null],
          "as": ["__count"]
        },
        {
          "type": "filter",
          "expr": "isValid(datum[\"bin_maxbins_10_Acceleration\"]) && isFinite(+datum[\"bin_maxbins_10_Acceleration\"]) && isValid(datum[\"bin_maxbins_10_Horsepower\"]) && isFinite(+datum[\"bin_maxbins_10_Horsepower\"])"
        }
      ]
    }
  ],
  "marks": [
    {
      "name": "layer_0_marks",
      "type": "symbol",
      "style": ["circle"],
      "from": {"data": "data_1"},
      "encode": {
        "update": {
          "fill": {"value": "#4c78a8"},
          "ariaRoleDescription": {"value": "circle"},
          "description": {
            "signal": "\"Acceleration (binned): \" + (!isValid(datum[\"bin_maxbins_10_Acceleration\"]) || !isFinite(+datum[\"bin_maxbins_10_Acceleration\"]) ? \"null\" : format(datum[\"bin_maxbins_10_Acceleration\"], \"\") + \" – \" + format(datum[\"bin_maxbins_10_Acceleration_end\"], \"\")) + \"; Horsepower (binned): \" + (!isValid(datum[\"bin_maxbins_10_Horsepower\"]) || !isFinite(+datum[\"bin_maxbins_10_Horsepower\"]) ? \"null\" : format(datum[\"bin_maxbins_10_Horsepower\"], \"\") + \" – \" + format(datum[\"bin_maxbins_10_Horsepower_end\"], \"\")) + \"; All Cars Count: \" + (format(datum[\"__count\"], \"\"))"
          },
          "x": {
            "signal": "scale(\"x\", 0.5 * datum[\"bin_maxbins_10_Acceleration\"] + 0.5 * datum[\"bin_maxbins_10_Acceleration_end\"])"
          },
          "y": {
            "signal": "scale(\"y\", 0.5 * datum[\"bin_maxbins_10_Horsepower\"] + 0.5 * datum[\"bin_maxbins_10_Horsepower_end\"])"
          },
          "size": {"scale": "size", "field": "__count"},
          "shape": {"value": "circle"}
        }
      }
    },
    {
      "name": "layer_1_marks",
      "type": "symbol",
      "style": ["circle"],
      "from": {"data": "data_0"},
      "encode": {
        "update": {
          "fill": {"value": "firebrick"},
          "ariaRoleDescription": {"value": "circle"},
          "description": {
            "signal": "\"Acceleration (binned): \" + (!isValid(datum[\"bin_maxbins_10_Acceleration\"]) || !isFinite(+datum[\"bin_maxbins_10_Acceleration\"]) ? \"null\" : format(datum[\"bin_maxbins_10_Acceleration\"], \"\") + \" – \" + format(datum[\"bin_maxbins_10_Acceleration_end\"], \"\")) + \"; Horsepower (binned): \" + (!isValid(datum[\"bin_maxbins_10_Horsepower\"]) || !isFinite(+datum[\"bin_maxbins_10_Horsepower\"]) ? \"null\" : format(datum[\"bin_maxbins_10_Horsepower\"], \"\") + \" – \" + format(datum[\"bin_maxbins_10_Horsepower_end\"], \"\")) + \"; Cars from Japan Count: \" + (format(datum[\"__count\"], \"\"))"
          },
          "x": {
            "signal": "scale(\"x\", 0.5 * datum[\"bin_maxbins_10_Acceleration\"] + 0.5 * datum[\"bin_maxbins_10_Acceleration_end\"])"
          },
          "y": {
            "signal": "scale(\"y\", 0.5 * datum[\"bin_maxbins_10_Horsepower\"] + 0.5 * datum[\"bin_maxbins_10_Horsepower_end\"])"
          },
          "size": {"scale": "size", "field": "__count"},
          "shape": {"value": "circle"}
        }
      }
    }
  ],
  "scales": [
    {
      "name": "x",
      "type": "linear",
      "domain": {
        "signal": "[layer_1_bin_maxbins_10_Acceleration_bins.start, layer_1_bin_maxbins_10_Acceleration_bins.stop]"
      },
      "range": [0, {"signal": "width"}],
      "bins": {"signal": "layer_1_bin_maxbins_10_Acceleration_bins"},
      "zero": false
    },
    {
      "name": "y",
      "type": "linear",
      "domain": {
        "signal": "[layer_1_bin_maxbins_10_Horsepower_bins.start, layer_1_bin_maxbins_10_Horsepower_bins.stop]"
      },
      "range": [{"signal": "height"}, 0],
      "bins": {"signal": "layer_1_bin_maxbins_10_Horsepower_bins"},
      "zero": false
    },
    {
      "name": "size",
      "type": "linear",
      "domain": {
        "fields": [
          {"data": "data_1", "field": "__count"},
          {"data": "data_0", "field": "__count"}
        ]
      },
      "range": [
        0,
        {
          "signal": "pow(0.95 * min(width / ((layer_1_bin_maxbins_10_Acceleration_bins.stop - layer_1_bin_maxbins_10_Acceleration_bins.start) / layer_1_bin_maxbins_10_Acceleration_bins.step), height / ((layer_1_bin_maxbins_10_Horsepower_bins.stop - layer_1_bin_maxbins_10_Horsepower_bins.start) / layer_1_bin_maxbins_10_Horsepower_bins.step)), 2)"
        }
      ],
      "zero": true
    }
  ],
  "axes": [
    {
      "scale": "x",
      "orient": "bottom",
      "grid": false,
      "title": "Acceleration (binned)",
      "labelFlush": true,
      "labelOverlap": true,
      "tickCount": {"signal": "ceil(width/10)"},
      "zindex": 0
    },
    {
      "scale": "y",
      "orient": "left",
      "grid": false,
      "title": "Horsepower (binned)",
      "labelOverlap": true,
      "tickCount": {"signal": "ceil(height/10)"},
      "zindex": 0
    }
  ],
  "legends": [
    {
      "title": "All Cars Count",
      "size": "size",
      "symbolType": "circle",
      "encode": {
        "symbols": {
          "update": {
            "fill": {"value": "#4c78a8"},
            "stroke": {"value": "transparent"}
          }
        }
      }
    },
    {
      "title": "Cars from Japan Count",
      "size": "size",
      "symbolType": "circle",
      "encode": {
        "symbols": {
          "update": {
            "fill": {"value": "firebrick"},
            "stroke": {"value": "transparent"}
          }
        }
      }
    }
  ]
}