{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "background": "white",
  "padding": 5,
  "width": 500,
  "height": 300,
  "data": [
    {"name": "source_0", "url": "data/airports.csv", "format": {"type": "csv"}},
    {
      "name": "data_0",
      "source": "source_0",
      "transform": [
        {
          "type": "geojson",
          "fields": ["longitude", "latitude"],
          "signal": "layer_0_geojson_0"
        },
        {
          "type": "geopoint",
          "projection": "projection",
          "fields": ["longitude", "latitude"],
          "as": ["layer_0_x", "layer_0_y"]
        }
      ]
    },
    {
      "name": "data_1",
      "source": "source_0",
      "transform": [
        {
          "type": "geojson",
          "fields": [{"expr": "-122.335167"}, "latitude"],
          "signal": "layer_1_geojson_0"
        },
        {
          "type": "geopoint",
          "projection": "projection",
          "fields": [{"expr": "-122.335167"}, "latitude"],
          "as": ["layer_1_x", "layer_1_y"]
        }
      ]
    },
    {
      "name": "data_2",
      "source": "source_0",
      "transform": [
        {
          "type": "geojson",
          "fields": ["longitude", {"expr": "47.608013"}],
          "signal": "layer_2_geojson_0"
        },
        {
          "type": "geopoint",
          "projection": "projection",
          "fields": ["longitude", {"expr": "47.608013"}],
          "as": ["layer_2_x", "layer_2_y"]
        }
      ]
    }
  ],
  "projections": [
    {
      "name": "projection",
      "size": {"signal": "[width, height]"},
      "fit": {
        "signal": "[layer_0_geojson_0, layer_1_geojson_0, layer_2_geojson_0]"
      },
      "type": "albersUsa"
    }
  ],
  "marks": [
    {
      "name": "layer_0_marks",
      "type": "symbol",
      "style": ["square"],
      "from": {"data": "data_0"},
      "encode": {
        "update": {
          "opacity": {"value": 0.7},
          "fill": {"value": "gray"},
          "ariaRoleDescription": {"value": "square"},
          "description": {
            "signal": "\"longitude: \" + (format(datum[\"longitude\"], \"\")) + \"; latitude: \" + (format(datum[\"latitude\"], \"\"))"
          },
          "x": {"field": "layer_0_x"},
          "y": {"field": "layer_0_y"},
          "size": {"value": 1},
          "shape": {"value": "square"}
        }
      }
    },
    {
      "name": "layer_1_marks",
      "type": "symbol",
      "style": ["square"],
      "from": {"data": "data_1"},
      "encode": {
        "update": {
          "opacity": {"value": 0.7},
          "fill": {"value": "steelblue"},
          "ariaRoleDescription": {"value": "square"},
          "description": {
            "signal": "\"latitude: \" + (format(datum[\"latitude\"], \"\"))"
          },
          "x": {"field": "layer_1_x"},
          "y": {"field": "layer_1_y"},
          "size": {"value": 1},
          "shape": {"value": "square"}
        }
      }
    },
    {
      "name": "layer_2_marks",
      "type": "symbol",
      "style": ["square"],
      "from": {"data": "data_2"},
      "encode": {
        "update": {
          "opacity": {"value": 0.7},
          "fill": {"value": "firebrick"},
          "ariaRoleDescription": {"value": "square"},
          "description": {
            "signal": "\"longitude: \" + (format(datum[\"longitude\"], \"\"))"
          },
          "x": {"field": "layer_2_x"},
          "y": {"field": "layer_2_y"},
          "size": {"value": 1},
          "shape": {"value": "square"}
        }
      }
    }
  ]
}