{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "description": "A dual axis chart, created by setting y's scale resolution to `\"independent\"`",
  "background": "white",
  "padding": 5,
  "width": 400,
  "height": 300,
  "style": "cell",
  "data": [
    {
      "name": "source_0",
      "url": "data/weather.csv",
      "format": {"type": "csv", "parse": {"date": "date"}},
      "transform": [
        {"type": "filter", "expr": "datum.location == \"Seattle\""},
        {
          "field": "date",
          "type": "timeunit",
          "units": ["month"],
          "as": ["month_date", "month_date_end"]
        },
        {
          "type": "aggregate",
          "groupby": ["month_date"],
          "ops": ["average", "average", "average"],
          "fields": ["temp_max", "temp_min", "precipitation"],
          "as": [
            "average_temp_max",
            "average_temp_min",
            "average_precipitation"
          ]
        }
      ]
    }
  ],
  "marks": [
    {
      "name": "layer_0_marks",
      "type": "area",
      "style": ["area"],
      "sort": {"field": "datum[\"month_date\"]"},
      "from": {"data": "source_0"},
      "encode": {
        "update": {
          "opacity": {"value": 0.3},
          "orient": {"value": "vertical"},
          "fill": {"value": "#85C5A6"},
          "description": {
            "signal": "\"date (month): \" + (timeFormat(datum[\"month_date\"], '%b')) + \"; Avg. Temperature (°C): \" + (format(datum[\"average_temp_max\"], \"\")) + \"; Average of temp_min: \" + (format(datum[\"average_temp_min\"], \"\"))"
          },
          "x": {"scale": "x", "field": "month_date"},
          "y": {"scale": "layer_0_y", "field": "average_temp_max"},
          "y2": {"scale": "layer_0_y", "field": "average_temp_min"},
          "defined": {
            "signal": "isValid(datum[\"month_date\"]) && isFinite(+datum[\"month_date\"]) && isValid(datum[\"average_temp_max\"]) && isFinite(+datum[\"average_temp_max\"])"
          }
        }
      }
    },
    {
      "name": "layer_1_marks",
      "type": "line",
      "style": ["line"],
      "sort": {"field": "datum[\"month_date\"]"},
      "from": {"data": "source_0"},
      "encode": {
        "update": {
          "stroke": {"value": "#85A9C5"},
          "interpolate": {"value": "monotone"},
          "description": {
            "signal": "\"date (month): \" + (timeFormat(datum[\"month_date\"], '%b')) + \"; Precipitation (inches): \" + (format(datum[\"average_precipitation\"], \"\"))"
          },
          "x": {"scale": "x", "field": "month_date"},
          "y": {"scale": "layer_1_y", "field": "average_precipitation"},
          "defined": {
            "signal": "isValid(datum[\"month_date\"]) && isFinite(+datum[\"month_date\"]) && isValid(datum[\"average_precipitation\"]) && isFinite(+datum[\"average_precipitation\"])"
          }
        }
      }
    }
  ],
  "scales": [
    {
      "name": "x",
      "type": "time",
      "domain": {"data": "source_0", "field": "month_date"},
      "range": [0, {"signal": "width"}]
    },
    {
      "name": "layer_0_y",
      "type": "linear",
      "domain": [0, 30],
      "range": [{"signal": "height"}, 0],
      "zero": true
    },
    {
      "name": "layer_1_y",
      "type": "linear",
      "domain": {"data": "source_0", "field": "average_precipitation"},
      "range": [{"signal": "height"}, 0],
      "nice": true,
      "zero": true
    }
  ],
  "axes": [
    {
      "scale": "x",
      "orient": "bottom",
      "gridScale": "layer_0_y",
      "grid": true,
      "domain": false,
      "labels": false,
      "aria": false,
      "maxExtent": 0,
      "minExtent": 0,
      "ticks": false,
      "zindex": 0
    },
    {
      "scale": "x",
      "orient": "bottom",
      "grid": false,
      "format": "%b",
      "labelFlush": true,
      "labelOverlap": true,
      "zindex": 0
    },
    {
      "scale": "layer_0_y",
      "orient": "left",
      "grid": false,
      "title": "Avg. Temperature (°C)",
      "titleColor": "#85C5A6",
      "labelOverlap": true,
      "tickCount": {"signal": "ceil(height/40)"},
      "zindex": 0
    },
    {
      "scale": "layer_1_y",
      "orient": "right",
      "grid": false,
      "title": "Precipitation (inches)",
      "titleColor": "#85A9C5",
      "labelOverlap": true,
      "tickCount": {"signal": "ceil(height/40)"},
      "zindex": 0
    }
  ]
}