{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "description": "Drag out a rectangular brush to highlight points.",
  "background": "white",
  "padding": 5,
  "height": 200,
  "data": [
    {"name": "hover_store"},
    {
      "name": "source_0",
      "url": "data/cars.json",
      "format": {"type": "json"},
      "transform": [{"type": "identifier", "as": "_vgsid_"}]
    },
    {
      "name": "data_0",
      "source": "source_0",
      "transform": [
        {
          "type": "filter",
          "expr": "isValid(datum[\"Horsepower\"]) && isFinite(+datum[\"Horsepower\"]) && isValid(datum[\"Miles_per_Gallon\"]) && isFinite(+datum[\"Miles_per_Gallon\"])"
        }
      ]
    },
    {
      "name": "data_1",
      "source": "source_0",
      "transform": [
        {
          "type": "filter",
          "expr": "isValid(datum[\"Horsepower\"]) && isFinite(+datum[\"Horsepower\"]) && isValid(datum[\"Acceleration\"]) && isFinite(+datum[\"Acceleration\"])"
        }
      ]
    }
  ],
  "signals": [
    {"name": "childWidth", "value": 200},
    {
      "name": "unit",
      "value": {},
      "on": [
        {"events": "mousemove", "update": "isTuple(group()) ? group() : unit"}
      ]
    },
    {
      "name": "hover",
      "update": "vlSelectionResolve(\"hover_store\", \"union\", true, true)"
    }
  ],
  "layout": {"padding": 20, "bounds": "full", "align": "each"},
  "marks": [
    {
      "type": "group",
      "name": "concat_0_group",
      "style": "cell",
      "encode": {
        "update": {
          "width": {"signal": "childWidth"},
          "height": {"signal": "height"}
        }
      },
      "signals": [
        {
          "name": "hover_tuple",
          "on": [
            {
              "events": [{"source": "scope", "type": "mouseover"}],
              "update": "datum && item().mark.marktype !== 'group' ? {unit: \"concat_0\", fields: hover_tuple_fields, values: [(item().isVoronoi ? datum.datum : datum)[\"_vgsid_\"]]} : null",
              "force": true
            },
            {
              "events": [{"source": "view", "type": "dblclick"}],
              "update": "null"
            }
          ]
        },
        {
          "name": "hover_tuple_fields",
          "value": [{"type": "E", "field": "_vgsid_"}]
        },
        {
          "name": "hover_toggle",
          "value": false,
          "on": [
            {
              "events": [{"source": "scope", "type": "mouseover"}],
              "update": "event.shiftKey"
            },
            {
              "events": [{"source": "view", "type": "dblclick"}],
              "update": "false"
            }
          ]
        },
        {
          "name": "hover_modify",
          "on": [
            {
              "events": {"signal": "hover_tuple"},
              "update": "modify(\"hover_store\", hover_toggle ? null : hover_tuple, hover_toggle ? null : true, hover_toggle ? hover_tuple : null)"
            }
          ]
        }
      ],
      "marks": [
        {
          "name": "concat_0_marks",
          "type": "symbol",
          "style": ["point"],
          "interactive": true,
          "from": {"data": "data_0"},
          "encode": {
            "update": {
              "opacity": {"value": 0.7},
              "fill": {"value": "transparent"},
              "stroke": [
                {
                  "test": "length(data(\"hover_store\")) && vlSelectionTest(\"hover_store\", datum)",
                  "scale": "color",
                  "field": "Cylinders"
                },
                {"value": "grey"}
              ],
              "ariaRoleDescription": {"value": "point"},
              "description": {
                "signal": "\"Horsepower: \" + (format(datum[\"Horsepower\"], \"\")) + \"; Miles_per_Gallon: \" + (format(datum[\"Miles_per_Gallon\"], \"\")) + \"; Cylinders: \" + (isValid(datum[\"Cylinders\"]) ? datum[\"Cylinders\"] : \"\"+datum[\"Cylinders\"])"
              },
              "x": {"scale": "concat_0_x", "field": "Horsepower"},
              "y": {"scale": "concat_0_y", "field": "Miles_per_Gallon"}
            }
          }
        }
      ],
      "axes": [
        {
          "scale": "concat_0_x",
          "orient": "bottom",
          "gridScale": "concat_0_y",
          "grid": true,
          "tickCount": {"signal": "ceil(childWidth/40)"},
          "domain": false,
          "labels": false,
          "aria": false,
          "maxExtent": 0,
          "minExtent": 0,
          "ticks": false,
          "zindex": 0
        },
        {
          "scale": "concat_0_y",
          "orient": "left",
          "gridScale": "concat_0_x",
          "grid": true,
          "tickCount": {"signal": "ceil(height/40)"},
          "domain": false,
          "labels": false,
          "aria": false,
          "maxExtent": 0,
          "minExtent": 0,
          "ticks": false,
          "zindex": 0
        },
        {
          "scale": "concat_0_x",
          "orient": "bottom",
          "grid": false,
          "title": "Horsepower",
          "labelFlush": true,
          "labelOverlap": true,
          "tickCount": {"signal": "ceil(childWidth/40)"},
          "zindex": 0
        },
        {
          "scale": "concat_0_y",
          "orient": "left",
          "grid": false,
          "title": "Miles_per_Gallon",
          "labelOverlap": true,
          "tickCount": {"signal": "ceil(height/40)"},
          "zindex": 0
        }
      ]
    },
    {
      "type": "group",
      "name": "concat_1_group",
      "style": "cell",
      "encode": {
        "update": {
          "width": {"signal": "childWidth"},
          "height": {"signal": "height"}
        }
      },
      "signals": [
        {
          "name": "hover_tuple",
          "on": [
            {
              "events": [{"source": "scope", "type": "mouseover"}],
              "update": "datum && item().mark.marktype !== 'group' ? {unit: \"concat_1\", fields: hover_tuple_fields, values: [(item().isVoronoi ? datum.datum : datum)[\"_vgsid_\"]]} : null",
              "force": true
            },
            {
              "events": [{"source": "view", "type": "dblclick"}],
              "update": "null"
            }
          ]
        },
        {
          "name": "hover_tuple_fields",
          "value": [{"type": "E", "field": "_vgsid_"}]
        },
        {
          "name": "hover_toggle",
          "value": false,
          "on": [
            {
              "events": [{"source": "scope", "type": "mouseover"}],
              "update": "event.shiftKey"
            },
            {
              "events": [{"source": "view", "type": "dblclick"}],
              "update": "false"
            }
          ]
        },
        {
          "name": "hover_modify",
          "on": [
            {
              "events": {"signal": "hover_tuple"},
              "update": "modify(\"hover_store\", hover_toggle ? null : hover_tuple, hover_toggle ? null : true, hover_toggle ? hover_tuple : null)"
            }
          ]
        }
      ],
      "marks": [
        {
          "name": "concat_1_marks",
          "type": "symbol",
          "style": ["point"],
          "interactive": true,
          "from": {"data": "data_1"},
          "encode": {
            "update": {
              "opacity": {"value": 0.7},
              "fill": {"value": "transparent"},
              "stroke": [
                {
                  "test": "length(data(\"hover_store\")) && vlSelectionTest(\"hover_store\", datum)",
                  "scale": "color",
                  "field": "Cylinders"
                },
                {"value": "grey"}
              ],
              "ariaRoleDescription": {"value": "point"},
              "description": {
                "signal": "\"Horsepower: \" + (format(datum[\"Horsepower\"], \"\")) + \"; Acceleration: \" + (format(datum[\"Acceleration\"], \"\")) + \"; Cylinders: \" + (isValid(datum[\"Cylinders\"]) ? datum[\"Cylinders\"] : \"\"+datum[\"Cylinders\"])"
              },
              "x": {"scale": "concat_1_x", "field": "Horsepower"},
              "y": {"scale": "concat_1_y", "field": "Acceleration"}
            }
          }
        }
      ],
      "axes": [
        {
          "scale": "concat_1_x",
          "orient": "bottom",
          "gridScale": "concat_1_y",
          "grid": true,
          "tickCount": {"signal": "ceil(childWidth/40)"},
          "domain": false,
          "labels": false,
          "aria": false,
          "maxExtent": 0,
          "minExtent": 0,
          "ticks": false,
          "zindex": 0
        },
        {
          "scale": "concat_1_y",
          "orient": "left",
          "gridScale": "concat_1_x",
          "grid": true,
          "tickCount": {"signal": "ceil(height/40)"},
          "domain": false,
          "labels": false,
          "aria": false,
          "maxExtent": 0,
          "minExtent": 0,
          "ticks": false,
          "zindex": 0
        },
        {
          "scale": "concat_1_x",
          "orient": "bottom",
          "grid": false,
          "title": "Horsepower",
          "labelFlush": true,
          "labelOverlap": true,
          "tickCount": {"signal": "ceil(childWidth/40)"},
          "zindex": 0
        },
        {
          "scale": "concat_1_y",
          "orient": "left",
          "grid": false,
          "title": "Acceleration",
          "labelOverlap": true,
          "tickCount": {"signal": "ceil(height/40)"},
          "zindex": 0
        }
      ]
    }
  ],
  "scales": [
    {
      "name": "color",
      "type": "ordinal",
      "domain": {
        "fields": [
          {"data": "data_0", "field": "Cylinders"},
          {"data": "data_1", "field": "Cylinders"}
        ],
        "sort": true
      },
      "range": "ordinal",
      "interpolate": "hcl"
    },
    {
      "name": "concat_0_x",
      "type": "linear",
      "domain": {"data": "data_0", "field": "Horsepower"},
      "range": [0, {"signal": "childWidth"}],
      "nice": true,
      "zero": true
    },
    {
      "name": "concat_0_y",
      "type": "linear",
      "domain": {"data": "data_0", "field": "Miles_per_Gallon"},
      "range": [{"signal": "height"}, 0],
      "nice": true,
      "zero": true
    },
    {
      "name": "concat_1_x",
      "type": "linear",
      "domain": {"data": "data_1", "field": "Horsepower"},
      "range": [0, {"signal": "childWidth"}],
      "nice": true,
      "zero": true
    },
    {
      "name": "concat_1_y",
      "type": "linear",
      "domain": {"data": "data_1", "field": "Acceleration"},
      "range": [{"signal": "height"}, 0],
      "nice": true,
      "zero": true
    }
  ],
  "legends": [
    {
      "stroke": "color",
      "symbolType": "circle",
      "title": "Cylinders",
      "encode": {
        "symbols": {
          "update": {
            "fill": {"value": "transparent"},
            "opacity": {"value": 0.7}
          }
        }
      }
    }
  ]
}