Sample Vega Spec for Comparison Operator

vega_compare_spec.json

{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "autosize": "pad",
  "padding": 5,
  "width": 200,
  "height": 200,
  "style": "cell",
  "data": [
    {"name": "sel1_store"},
    {"name": "sel2_store"},
    {
      "name": "source_0",
      "url": "data/cars.json",
      "format": {"type": "json"},
      "transform": [
        {
          "type": "filter",
          "expr": "datum[\"Horsepower\"] !== null && !isNaN(datum[\"Horsepower\"]) && datum[\"Miles_per_Gallon\"] !== null && !isNaN(datum[\"Miles_per_Gallon\"])"
        }
      ]
    },
  {
    "name": "sel1_aggregates",
    "source": "source_0",
    "transform": [
      {"type":"filter", "expr": "datum.Origin == vlSelectionResolve(\"sel1_store\").Origin"},
      {
        "type": "aggregate",
        "fields": ["Cylinders", "Horsepower"],
        "ops": ["min", "mean"],
        "as": ["CylMIN", "HorsepowerMEAN"]
      }
      ]
    },
      {
    "name": "sel2_aggregates",
    "source": "source_0",
    "transform": [
      {"type":"filter", "expr": "datum.Horsepower == vlSelectionResolve(\"sel2_store\").Horsepower && datum.Cylinders == vlSelectionResolve(\"sel2_store\").Cylinders"},
      {
        "type": "aggregate",
        "fields": ["Miles_per_Gallon"],
        "ops": ["mean"],
        "as": ["MilesGallonMEAN"]
      }
      ]
    },
    {
      "name": "test_store",
      "source": "source_0",
      "transform": [
        {"type":"filter", "expr": "datum.Cylinders > (data(\"sel1_aggregates\")[0] && data(\"sel1_aggregates\")[0].CylMIN) && datum.Horsepower != (data(\"sel1_aggregates\")[0] && data(\"sel1_aggregates\")[0].HorsepowerMEAN) && datum.Miles_per_Gallon >= (data(\"sel2_aggregates\")[0] && data(\"sel2_aggregates\")[0].MilesGallonMEAN)"}
      ]
    }
  ],
  "signals": [
    {
      "name": "unit",
      "value": {},
      "on": [
        {"events": "mousemove", "update": "isTuple(group()) ? group() : unit"}
      ]
    },
    {"name": "sel1", "update": "vlSelectionResolve(\"sel1_store\")"},
    {"name": "sel2", "update": "vlSelectionResolve(\"sel2_store\")"},
        {
      "name": "sample_signal",
      "on": [
        {
          "events": [{"source": "scope", "type": "click"}],
          "update": "data(\"sel1_aggregates\")[0] && data(\"sel1_aggregates\")[0].CylMIN"
        }
      ]
    },
    {
      "name": "sel1_tuple",
      "on": [
        {
          "events": [{"source": "scope", "type": "click"}],
          "update": "datum && item().mark.marktype !== 'group' ? {unit: \"\", fields: sel1_tuple_fields, values: [(item().isVoronoi ? datum.datum : datum)[\"Origin\"]]} : null",
          "force": true
        },
        {"events": [{"source": "scope", "type": "dblclick"}], "update": "null"}
      ]
    },
    {"name": "sel1_tuple_fields", "value": [{"type": "E", "field": "Origin"}]},
    {
      "name": "sel1_toggle",
      "value": false,
      "on": [
        {
          "events": [{"source": "scope", "type": "click"}],
          "update": "event.shiftKey"
        },
        {"events": [{"source": "scope", "type": "dblclick"}], "update": "false"}
      ]
    },
    {
      "name": "sel1_modify",
      "update": "modify(\"sel1_store\", sel1_toggle ? null : sel1_tuple, sel1_toggle ? null : true, sel1_toggle ? sel1_tuple : null)"
    },
    {
      "name": "sel2_tuple",
      "on": [
        {
          "events": [{"source": "scope", "type": "click"}],
          "update": "datum && item().mark.marktype !== 'group' ? {unit: \"\", fields: sel2_tuple_fields, values: [(item().isVoronoi ? datum.datum : datum)[\"Horsepower\"], (item().isVoronoi ? datum.datum : datum)[\"Cylinders\"]]} : null",
          "force": true
        },
        {"events": [{"source": "scope", "type": "dblclick"}], "update": "null"}
      ]
    },
    {
      "name": "sel2_tuple_fields",
      "value": [
        {"type": "E", "field": "Horsepower"},
        {"type": "E", "field": "Cylinders"}
      ]
    },
    {
      "name": "sel2_toggle",
      "value": false,
      "on": [
        {
          "events": [{"source": "scope", "type": "click"}],
          "update": "event.shiftKey"
        },
        {"events": [{"source": "scope", "type": "dblclick"}], "update": "false"}
      ]
    },
    {
      "name": "sel2_modify",
      "update": "modify(\"sel2_store\", sel2_toggle ? null : sel2_tuple, sel2_toggle ? null : true, sel2_toggle ? sel2_tuple : null)"
    }
  ],
  "marks": [
    {
      "name": "marks",
      "type": "symbol",
      "style": ["circle"],
      "from": {"data": "source_0"},
      "encode": {
        "update": {
          "opacity": {"value": 0.7},
          "fill": [
            {
              "test": "!(length(data(\"sel1_store\"))) || (vlSelectionTest(\"sel1_store\", datum))",
              "scale": "color",
              "field": "Origin"
            },
            {"value": "grey"}
          ],
          "tooltip": {
            "signal": "{\"Horsepower\": format(datum[\"Horsepower\"], \"\"), \"Miles_per_Gallon\": format(datum[\"Miles_per_Gallon\"], \"\"), \"Origin\": ''+datum[\"Origin\"]}"
          },
          "x": {"scale": "x", "field": "Horsepower"},
          "y": {"scale": "y", "field": "Miles_per_Gallon"},
          "shape": {"value": "circle"}
        }
      }
    }
  ],
  "scales": [
    {
      "name": "x",
      "type": "linear",
      "domain": {"data": "source_0", "field": "Horsepower"},
      "range": [0, {"signal": "width"}],
      "nice": true,
      "zero": true
    },
    {
      "name": "y",
      "type": "linear",
      "domain": {"data": "source_0", "field": "Miles_per_Gallon"},
      "range": [{"signal": "height"}, 0],
      "nice": true,
      "zero": true
    },
    {
      "name": "color",
      "type": "ordinal",
      "domain": {"data": "source_0", "field": "Origin", "sort": true},
      "range": "category"
    }
  ],
  "axes": [
    {
      "scale": "x",
      "orient": "bottom",
      "grid": false,
      "title": "Horsepower",
      "labelFlush": true,
      "labelOverlap": true,
      "tickCount": {"signal": "ceil(width/40)"},
      "zindex": 1
    },
    {
      "scale": "x",
      "orient": "bottom",
      "gridScale": "y",
      "grid": true,
      "tickCount": {"signal": "ceil(width/40)"},
      "domain": false,
      "labels": false,
      "maxExtent": 0,
      "minExtent": 0,
      "ticks": false,
      "zindex": 0
    },
    {
      "scale": "y",
      "orient": "left",
      "grid": false,
      "title": "Miles_per_Gallon",
      "labelOverlap": true,
      "tickCount": {"signal": "ceil(height/40)"},
      "zindex": 1
    },
    {
      "scale": "y",
      "orient": "left",
      "gridScale": "x",
      "grid": true,
      "tickCount": {"signal": "ceil(height/40)"},
      "domain": false,
      "labels": false,
      "maxExtent": 0,
      "minExtent": 0,
      "ticks": false,
      "zindex": 0
    }
  ],
  "legends": [
    {
      "fill": "color",
      "gradientLength": {"signal": "clamp(height, 64, 200)"},
      "symbolType": "circle",
      "title": "Origin",
      "encode": {
        "symbols": {
          "update": {"shape": {"value": "circle"}, "opacity": {"value": 0.7}}
        }
      }
    }
  ]
}