Error Bar with Standard Deviation

This example shows how to show error bars with standard deviation using crop yields data of different in the years of 1930s.

import altair as alt
from vega_datasets import data

source = data.barley()

error_bars = alt.Chart(source).mark_errorbar(extent='stdev').encode(
  x=alt.X('yield:Q', scale=alt.Scale(zero=False)),

points = alt.Chart(source).mark_point(filled=True, color='black').encode(
  x=alt.X('yield:Q', aggregate='mean'),

error_bars + points