{
    "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
    "data": {
        "format": {
            "parse": {
                "Release_Date": "date:'%d-%b-%y'"
            }
        },
        "url": "https://vega.github.io/vega-lite/data/movies.json"
    },
    "description": "Calculation of difference from annual average",
    "layer": [
        {
            "encoding": {
                "x": {
                    "axis": {
                        "title": "IMDB Rating"
                    },
                    "field": "IMDB_Rating",
                    "type": "quantitative"
                },
                "y": {
                    "field": "Title",
                    "type": "ordinal"
                }
            },
            "mark": {
                "clip": true,
                "type": "bar"
            }
        },
        {
            "encoding": {
                "color": {
                    "value": "red"
                },
                "x": {
                    "field": "AverageYearRating",
                    "type": "quantitative"
                },
                "y": {
                    "field": "Title",
                    "type": "ordinal"
                }
            },
            "mark": "tick"
        }
    ],
    "transform": [
        {
            "filter": "isValid(datum.IMDB_Rating)"
        },
        {
            "as": "year",
            "field": "Release_Date",
            "timeUnit": "year"
        },
        {
            "frame": [
                null,
                null
            ],
            "groupby": [
                "year"
            ],
            "window": [
                {
                    "as": "AverageYearRating",
                    "field": "IMDB_Rating",
                    "op": "mean"
                }
            ]
        },
        {
            "filter": "(datum.IMDB_Rating - datum.AverageYearRating) > 2.5"
        }
    ]
}