DOC: Simplified trail chart and moved it into line charts section
"""
-Trail Marker
-------------
-The ``trail`` marker is like the ``line`` marker, but it allows properties of
-the line (such as thickness) to vary along the length of the line.
-This shows a simple example of the trail mark using stock prices.
+Line Chart with Varying Size
+----------------------------
+This is example of using the ``trail`` marker to vary the size of a line.
"""
-# category: other charts
+# category: line charts
import altair as alt
from vega_datasets import data
-source = data.stocks()
+source = data.wheat()
alt.Chart(source).mark_trail().encode(
- x='date:T',
- y='price:Q',
- size='price:Q',
- color='symbol:N'
+ x='year:T',
+ y='wheat:Q',
+ size='wheat:Q'
)
