{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "background": "white",
  "padding": 5,
  "width": 200,
  "height": 200,
  "style": "cell",
  "data": [
    {
      "name": "source_0",
      "values": [
        {"a": 0, "b": 28, "c": 0},
        {"a": 0, "b": 91, "c": 1},
        {"a": 1, "b": 43, "c": 0},
        {"a": 1, "b": 55, "c": 1},
        {"a": 2, "b": 81, "c": 0},
        {"a": 2, "b": 53, "c": 1},
        {"a": 3, "b": 19, "c": 0}
      ]
    },
    {
      "name": "data_0",
      "source": "source_0",
      "transform": [
        {"type": "formula", "expr": "toNumber(datum[\"a\"])", "as": "a"},
        {
          "type": "impute",
          "field": "b",
          "key": "a",
          "keyvals": [4],
          "method": "value",
          "groupby": ["c"],
          "value": 100
        }
      ]
    }
  ],
  "marks": [
    {
      "name": "pathgroup",
      "type": "group",
      "from": {
        "facet": {
          "name": "faceted_path_main",
          "data": "data_0",
          "groupby": ["c"]
        }
      },
      "encode": {
        "update": {
          "width": {"field": {"group": "width"}},
          "height": {"field": {"group": "height"}}
        }
      },
      "marks": [
        {
          "name": "marks",
          "type": "line",
          "style": ["line"],
          "sort": {"field": "datum[\"a\"]"},
          "from": {"data": "faceted_path_main"},
          "encode": {
            "update": {
              "stroke": {"scale": "color", "field": "c"},
              "description": {
                "signal": "\"a: \" + (format(datum[\"a\"], \"\")) + \"; b: \" + (format(datum[\"b\"], \"\")) + \"; c: \" + (isValid(datum[\"c\"]) ? datum[\"c\"] : \"\"+datum[\"c\"])"
              },
              "x": {"scale": "x", "field": "a"},
              "y": {"scale": "y", "field": "b"},
              "defined": {
                "signal": "isValid(datum[\"a\"]) && isFinite(+datum[\"a\"]) && isValid(datum[\"b\"]) && isFinite(+datum[\"b\"])"
              }
            }
          }
        }
      ]
    }
  ],
  "scales": [
    {
      "name": "x",
      "type": "linear",
      "domain": {"data": "data_0", "field": "a"},
      "range": [0, {"signal": "width"}],
      "nice": 1,
      "zero": false
    },
    {
      "name": "y",
      "type": "linear",
      "domain": {"data": "data_0", "field": "b"},
      "range": [{"signal": "height"}, 0],
      "nice": true,
      "zero": true
    },
    {
      "name": "color",
      "type": "ordinal",
      "domain": {"data": "data_0", "field": "c", "sort": true},
      "range": "category"
    }
  ],
  "axes": [
    {
      "scale": "x",
      "orient": "bottom",
      "gridScale": "y",
      "grid": true,
      "tickCount": {"signal": "ceil(width/40)"},
      "domain": false,
      "labels": false,
      "aria": false,
      "maxExtent": 0,
      "minExtent": 0,
      "ticks": false,
      "zindex": 0
    },
    {
      "scale": "y",
      "orient": "left",
      "gridScale": "x",
      "grid": true,
      "tickCount": {"signal": "ceil(height/40)"},
      "domain": false,
      "labels": false,
      "aria": false,
      "maxExtent": 0,
      "minExtent": 0,
      "ticks": false,
      "zindex": 0
    },
    {
      "scale": "x",
      "orient": "bottom",
      "grid": false,
      "title": "a",
      "labelFlush": true,
      "labelOverlap": true,
      "tickCount": {"signal": "ceil(width/40)"},
      "zindex": 0
    },
    {
      "scale": "y",
      "orient": "left",
      "grid": false,
      "title": "b",
      "labelOverlap": true,
      "tickCount": {"signal": "ceil(height/40)"},
      "zindex": 0
    }
  ],
  "legends": [{"stroke": "color", "symbolType": "stroke", "title": "c"}]
}