2022-05-23 00:16:32 +04:00

33 lines
787 B
Python

"""
Line Chart with datum
---------------------------------
An example of using ``datum`` to highlight certain values, including a ``DateTime`` value.
This is adapted from two corresponding Vega-Lite Examples:
`Highlight a Specific Value <https://vega.github.io/vega-lite/docs/datum.html#highlight-a-specific-data-value>`_.
"""
# category: line charts
import altair as alt
from vega_datasets import data
source = data.stocks()
lines = (
alt.Chart(source)
.mark_line()
.encode(x="date", y="price", color="symbol")
)
xrule = (
alt.Chart()
.mark_rule(color="cyan", strokeWidth=2)
.encode(x=alt.datum(alt.DateTime(year=2006, month="November")))
)
yrule = (
alt.Chart().mark_rule(strokeDash=[12, 6], size=2).encode(y=alt.datum(350))
)
lines + yrule + xrule