CODEWITHSUNDEEP
pythonaltair
bayesways
bayesways

Reputation: 53

Set subtitles font size on facet charts in Altair

How can I edit the font size of the years appearing above each subgraph in the example below: Take from the altair gallery

import altair as alt
from vega_datasets import data

source = data.population.url

alt.Chart(source).mark_area().encode(
    x='age:O',
    y=alt.Y(
        'sum(people):Q',
        title='Population',
        axis=alt.Axis(format='~s')
    ),
    facet=alt.Facet('year:O', columns=5),
).properties(
    title='US Age Distribution By Year',
    width=90,
    height=80
)

Upvotes: 1

Views: 2961

Answers (1)

jakevdp
jakevdp

Reputation: 86330

You can set this using labelFontSize in the header property of the facet encoding:

import altair as alt
from vega_datasets import data

source = data.population.url

alt.Chart(source).mark_area().encode(
    x='age:O',
    y=alt.Y(
        'sum(people):Q',
        title='Population',
        axis=alt.Axis(format='~s')
    ),
    facet=alt.Facet(
        'year:O', columns=5,
        header=alt.Header(labelFontSize=20)
    ),
).properties(
    title='US Age Distribution By Year',
    width=90,
    height=80
)

enter image description here

For the full list and description of available header properties, see https://altair-viz.github.io/user_guide/generated/core/altair.Header.html

Upvotes: 3

Related Questions