layer_line_exponential.vl.json

{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "width": 400,
  "data": {
    "values": [
      {"price": 9.2, "year": 2020},
      {"price": 10.76, "year": 2020},
      {"price": 36.88, "year": 2021},
      {"price": 3.44, "year": 2021},
      {"price": 10.55, "year": 2022},
      {"price": 9.65, "year": 2022},
      {"price": 7.15, "year": 2023},
      {"price": 15.0, "year": 2023},
      {"price": 10.19, "year": 2024},
      {"price": 8.86, "year": 2024}
    ]
  },
  "layer": [
    {
      "mark": "line",
      "encoding": {
        "x": {
          "field": "year"
        },
        "y": {
          "field": "price",
          "aggregate": "mean",
          "type": "quantitative",
          "title": "Avg Price"
        }
      }
    },
    {
      "mark": {
        "type": "line",
        "opacity": 0.5
      },
      "encoding": {
        "x": {
          "field": "year"
        },
        "y": {
          "field": "price",
          "aggregate": {
            "exponential": 0.5
          },
          "type": "quantitative"
        }
      }
    }
  ]
}