window4.vl

{
    "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
    "data": {
        "format": {
            "parse": {
                "Release_Date": "date:'%b %d %Y'"
            }
        },
        "url": "https://vega.github.io/vega-lite/data/movies.json"
    },
    "encoding": {
        "x": {
            "field": "Release_Date",
            "type": "temporal"
        },
        "y": {
            "axis": {
                "title": "Residual"
            },
            "field": "RatingDelta",
            "type": "quantitative"
        }
    },
    "mark": {
        "opacity": 0.3,
        "strokeWidth": 0.3,
        "type": "point"
    },
    "transform": [
        {
            "filter": "datum.IMDB_Rating != null"
        },
        {
            "filter": {
                "field": "Release_Date",
                "range": [
                    null,
                    {
                        "year": 2019
                    }
                ]
            }
        },
        {
            "frame": [
                null,
                null
            ],
            "window": [
                {
                    "as": "AverageRating",
                    "field": "IMDB_Rating",
                    "op": "mean"
                }
            ]
        },
        {
            "as": "RatingDelta",
            "calculate": "datum.IMDB_Rating - datum.AverageRating"
        }
    ]
}