[altair-snippets] altair snippets #python #altair #visualization

linked-brush-selection.py

# load an example dataset
from vega_datasets import data
cars = data.cars()

import altair as alt

interval = alt.selection_interval()

base = alt.Chart(cars).mark_point().encode(
  y='Miles_per_Gallon',
  color=alt.condition(interval, 'Origin', alt.value('lightgray'))
).properties(
  selection=interval
)

# 这个非常好，使用encode来填充确实的参数，便于做灵活的FacetGrid的图形
base.encode(x='Acceleration') | base.encode(x='Horsepower')

scatter-plot-with-rolling-mean.py

# load an example dataset
from vega_datasets import data
cars = data.cars()

import altair as alt

# 年为X轴，数值为Y，可以看到一年内多个不同的数值为一个竖线。使用Origin做颜色的分类。
points = alt.Chart(cars).mark_point().encode(
  x='Year:T',
  y='Miles_per_Gallon',
  color='Origin'
).properties(
  width=800
)

# 平均值折线计算
lines = alt.Chart(cars).mark_line().encode(
  x='Year:T',
  y='mean(Miles_per_Gallon)',
  color='Origin'
).properties(
  width=800
).interactive(bind_y=False)
              
# 使用+放在一个图中
points + lines