brushing_linking.json

{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "data": [
    {"name": "my_selection_store"},
    {
      "name": "cars",
      "url": "https://raw.githubusercontent.com/vega/vega/master/docs/data/cars.json",
      "format": {"type": "json"}
    }
  ],
  "signals": [
    {"name": "plot0_width", "value": 200},
    {"name": "plot0_height", "value": 200},
    {"name": "plot1_width", "value": 200},
    {"name": "plot1_height", "value": 200},
    {
      "name": "unit",
      "value": {},
      "on": [
        {"events": "mousemove", "update": "isTuple(group()) ? group() : unit"}
      ]
    },
    {
      "name": "my_selection",
      "update": "vlSelectionResolve(\"my_selection_store\", \"union\")"
    }
  ],
  "layout": {"padding": 20, "bounds": "full", "align": "each"},
  "marks": [
    {
      "type": "group",
      "name": "plot0_group",
      "style": "cell",
      "encode": {
        "update": {
          "width": {"signal": "plot0_width"},
          "height": {"signal": "plot0_height"}
        }
      },
      "signals": [
        {
          "name": "my_selection_x",
          "value": [],
          "on": [
            {
              "events": {
                "source": "scope",
                "type": "mousedown",
                "filter": [
                  "event.item.mark.name !== \"my_selection_brush\""
                ]
              },
              "update": "[x(unit), x(unit)]"
            },
            {
              "events": {
                "source": "window",
                "type": "mousemove",
                "consume": true,
                "between": [
                  {
                    "source": "scope",
                    "type": "mousedown",
                    "filter": [
                      "event.item.mark.name !== \"my_selection_brush\""
                    ]
                  },
                  {"source": "window", "type": "mouseup"}
                ]
              },
              "update": "[my_selection_x[0], clamp(x(unit), 0, plot0_width)]"
            },
            {
              "events": {"signal": "my_selection_translate_delta"},
              "update": "clampRange(panLinear(my_selection_translate_anchor.extent_x, my_selection_translate_delta.x / span(my_selection_translate_anchor.extent_x)), 0, plot0_width)"
            }
          ]
        },
        {
          "name": "my_selection_Weight_in_lbs",
          "on": [
            {
              "events": {"signal": "my_selection_x"},
              "update": "my_selection_x[0] === my_selection_x[1] ? null : invert(\"plot0_x\", my_selection_x)"
            }
          ]
        },
        {
          "name": "my_selection_y",
          "value": [],
          "on": [
            {
              "events": {
                "source": "scope",
                "type": "mousedown",
                "filter": [
                  "event.item.mark.name !== \"my_selection_brush\""
                ]
              },
              "update": "[y(unit), y(unit)]"
            },
            {
              "events": {
                "source": "window",
                "type": "mousemove",
                "consume": true,
                "between": [
                  {
                    "source": "scope",
                    "type": "mousedown",
                    "filter": [
                      "event.item.mark.name !== \"my_selection_brush\""
                    ]
                  },
                  {"source": "window", "type": "mouseup"}
                ]
              },
              "update": "[my_selection_y[0], clamp(y(unit), 0, plot0_height)]"
            },
            {
              "events": {"signal": "my_selection_translate_delta"},
              "update": "clampRange(panLinear(my_selection_translate_anchor.extent_y, my_selection_translate_delta.y / span(my_selection_translate_anchor.extent_y)), 0, plot0_height)"
            }
          ]
        },
        {
          "name": "my_selection_Miles_per_Gallon",
          "on": [
            {
              "events": {"signal": "my_selection_y"},
              "update": "my_selection_y[0] === my_selection_y[1] ? null : invert(\"plot0_y\", my_selection_y)"
            }
          ]
        },
        {
          "name": "my_selection_tuple",
          "on": [
            {
              "events": [
                {
                  "signal": "my_selection_Weight_in_lbs || my_selection_Miles_per_Gallon"
                }
              ],
              "update": "my_selection_Weight_in_lbs && my_selection_Miles_per_Gallon ? {unit: \"plot0\", fields: my_selection_tuple_fields, values: [my_selection_Weight_in_lbs,my_selection_Miles_per_Gallon]} : null"
            }
          ]
        },
        {
          "name": "my_selection_tuple_fields",
          "value": [
            {"field": "Weight_in_lbs", "channel": "x", "type": "R"},
            {"field": "Miles_per_Gallon", "channel": "y", "type": "R"}
          ]
        },
        {
          "name": "my_selection_translate_anchor",
          "value": {},
          "on": [
            {
              "events": [
                {
                  "source": "scope",
                  "type": "mousedown",
                  "markname": "my_selection_brush"
                }
              ],
              "update": "{x: x(unit), y: y(unit), extent_x: slice(my_selection_x), extent_y: slice(my_selection_y)}"
            }
          ]
        },
        {
          "name": "my_selection_translate_delta",
          "value": {},
          "on": [
            {
              "events": [
                {
                  "source": "window",
                  "type": "mousemove",
                  "consume": true,
                  "between": [
                    {
                      "source": "scope",
                      "type": "mousedown",
                      "markname": "my_selection_brush"
                    },
                    {"source": "window", "type": "mouseup"}
                  ]
                }
              ],
              "update": "{x: my_selection_translate_anchor.x - x(unit), y: my_selection_translate_anchor.y - y(unit)}"
            }
          ]
        },
        {
          "name": "my_selection_modify",
          "on": [
            {
              "events": {"signal": "my_selection_tuple"},
              "update": "modify(\"my_selection_store\", my_selection_tuple, true)"
            }
          ]
        }
      ],
      "marks": [
        {
          "name": "my_selection_brush_bg",
          "type": "rect",
          "clip": true,
          "encode": {
            "enter": {
              "fill": {"value": "#333"},
              "fillOpacity": {"value": 0.125}
            },
            "update": {
              "x": [
                {
                  "test": "data(\"my_selection_store\").length && data(\"my_selection_store\")[0].unit === \"plot0\"",
                  "signal": "my_selection_x[0]"
                },
                {"value": 0}
              ],
              "y": [
                {
                  "test": "data(\"my_selection_store\").length && data(\"my_selection_store\")[0].unit === \"plot0\"",
                  "signal": "my_selection_y[0]"
                },
                {"value": 0}
              ],
              "x2": [
                {
                  "test": "data(\"my_selection_store\").length && data(\"my_selection_store\")[0].unit === \"plot0\"",
                  "signal": "my_selection_x[1]"
                },
                {"value": 0}
              ],
              "y2": [
                {
                  "test": "data(\"my_selection_store\").length && data(\"my_selection_store\")[0].unit === \"plot0\"",
                  "signal": "my_selection_y[1]"
                },
                {"value": 0}
              ]
            }
          }
        },
        {
          "name": "plot0_marks",
          "type": "symbol",
          "style": ["circle"],
          "interactive": true,
          "from": {"data": "cars"},
          "encode": {
            "update": {
              "opacity": {"value": 0.7},
              "fill": [
                {
                  "test": "(vlSelectionTest(\"my_selection_store\", datum))",
                  "value": "red"
                },
                {"value": "lightgrey"}
              ],
              "x": {"scale": "plot0_x", "field": "Weight_in_lbs"},
              "y": {"scale": "plot0_y", "field": "Miles_per_Gallon"},
              "shape": {"value": "circle"}
            }
          }
        },
        {
          "name": "my_selection_brush",
          "type": "rect",
          "clip": true,
          "encode": {
            "enter": {"fill": {"value": "transparent"}},
            "update": {
              "x": [
                {
                  "test": "data(\"my_selection_store\").length && data(\"my_selection_store\")[0].unit === \"plot0\"",
                  "signal": "my_selection_x[0]"
                },
                {"value": 0}
              ],
              "y": [
                {
                  "test": "data(\"my_selection_store\").length && data(\"my_selection_store\")[0].unit === \"plot0\"",
                  "signal": "my_selection_y[0]"
                },
                {"value": 0}
              ],
              "x2": [
                {
                  "test": "data(\"my_selection_store\").length && data(\"my_selection_store\")[0].unit === \"plot0\"",
                  "signal": "my_selection_x[1]"
                },
                {"value": 0}
              ],
              "y2": [
                {
                  "test": "data(\"my_selection_store\").length && data(\"my_selection_store\")[0].unit === \"plot0\"",
                  "signal": "my_selection_y[1]"
                },
                {"value": 0}
              ],
              "stroke": [
                {
                  "test": "my_selection_x[0] !== my_selection_x[1] && my_selection_y[0] !== my_selection_y[1]",
                  "value": "white"
                },
                {"value": null}
              ]
            }
          }
        }
      ]
    },
    {
      "type": "group",
      "name": "plot1_group",
      "style": "cell",
      "encode": {
        "update": {
          "width": {"signal": "plot1_width"},
          "height": {"signal": "plot1_height"}
        }
      },
      "marks": [
        {
          "name": "plot1_marks",
          "type": "symbol",
          "style": ["circle"],
          "interactive": false,
          "from": {"data": "cars"},
          "encode": {
            "update": {
              "opacity": {"value": 0.7},
              "fill": [
                {
                  "test": "(vlSelectionTest(\"my_selection_store\", datum))",
                  "value": "red"
                },
                {"value": "lightgrey"}
              ],
              "x": {"scale": "plot1_x", "field": "Acceleration"},
              "y": {"scale": "plot1_y", "field": "Horsepower"},
              "shape": {"value": "circle"}
            }
          }
        }
      ]
    }
  ],
  "scales": [
    {
      "name": "plot0_x",
      "type": "linear",
      "domain": {"data": "cars", "field": "Weight_in_lbs"},
      "range": [0, {"signal": "plot0_width"}],
      "nice": true,
      "zero": true
    },
    {
      "name": "plot0_y",
      "type": "linear",
      "domain": {"data": "cars", "field": "Miles_per_Gallon"},
      "range": [{"signal": "plot0_height"}, 0],
      "nice": true,
      "zero": true
    },
    {
      "name": "plot1_x",
      "type": "linear",
      "domain": {"data": "cars", "field": "Acceleration"},
      "range": [0, {"signal": "plot1_width"}],
      "nice": true,
      "zero": true
    },
    {
      "name": "plot1_y",
      "type": "linear",
      "domain": {"data": "cars", "field": "Horsepower"},
      "range": [{"signal": "plot1_height"}, 0],
      "nice": true,
      "zero": true
    }
  ]
}