计算残差

点图显示数据库中的每部电影及其与平均电影评分的差值。显示按年份排序，以便按顺序可视化所有内容。此图显示 2019 年之前的电影。

改编自 计算残差。

方法语法

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

属性语法

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