填充阶梯图

本示例显示了谷歌的股票价格随时间变化的阶梯图，区域被填充，并强调了其线条。

Method syntax

import altair as alt
from vega_datasets import data

source = data.stocks()

alt.Chart(source).mark_area(
    color="lightblue",
    interpolate='step-after',
    line=True
).encode(
    x='date',
    y='price'
).transform_filter(alt.datum.symbol == 'GOOG')

Attribute syntax

import altair as alt
from vega_datasets import data

source = data.stocks()

alt.Chart(source).mark_area(
    color="lightblue",
    interpolate='step-after',
    line=True
).encode(
    x='date',
    y='price'
).transform_filter(alt.datum.symbol == 'GOOG')
# No channel encoding options are specified in this chart
# so the code is the same as for the method-based syntax.