Calculate Residuals

A dot plot showing each movie in the database, and the difference from the average movie rating. The display is sorted by year to visualize everything in sequential order. The graph is for all Movies before 2019.

Adapted from Calculate Residuals.

Method syntax

import altair as alt
from vega_datasets import data

imdb_rating = alt.datum["IMDB_Rating"]
source = data.movies.url

chart = (
    alt.Chart(source)
    .mark_point()
    .transform_filter(imdb_rating != None)
    .transform_filter(
        alt.FieldRangePredicate("Release_Date", [None, 2019], timeUnit="year")
    )
    .transform_joinaggregate(Average_Rating="mean(IMDB_Rating)")
    .transform_calculate(Rating_Delta=imdb_rating - alt.datum.Average_Rating)
    .encode(
        x=alt.X("Release_Date:T").title("Release Date"),
        y=alt.Y("Rating_Delta:Q").title("Rating Delta"),
        color=alt.Color("Rating_Delta:Q").title("Rating Delta").scale(domainMid=0),
    )
)
chart

Attribute syntax

import altair as alt
from vega_datasets import data

imdb_rating = alt.datum["IMDB_Rating"]
source = data.movies.url

chart = (
    alt.Chart(source)
    .mark_point()
    .transform_filter(imdb_rating != None)
    .transform_filter(
        alt.FieldRangePredicate("Release_Date", [None, 2019], timeUnit="year")
    )
    .transform_joinaggregate(Average_Rating="mean(IMDB_Rating)")
    .transform_calculate(Rating_Delta=imdb_rating - alt.datum.Average_Rating)
    .encode(
        x=alt.X("Release_Date:T", title="Release Date"),
        y=alt.Y("Rating_Delta:Q", title="Rating Delta"),
        color=alt.Color(
            "Rating_Delta:Q",
            title="Rating Delta",
            scale=alt.Scale(domainMid=0),
        ),
    )
)
chart