如何制作具有跨列一致网格的分组条形图?

How do I make a grouped bar chart with a consistent grid across columns?

我正在尝试在 Altair 中制作一个分组条形图,其中的列不是很明显(可能通过删除它们之间的 space)。

问题here relies on several depreciated methods. Additionally, the desired visual grouping described there (which is what I'm looking for) was closed as a vega-lite issue. This has since been resolved中提出的解决方案。

是否有更新的方法来创建分组清晰的条形图?

这是我目前的情况:

import pandas as pd
import numpy as np
import altair as alt

vals = np.concatenate(((np.arange(10) ** 2) / 9, np.arange(10)))
df = pd.DataFrame({
    'cat': np.repeat(['a', 'b'], 10),
    'x': np.tile(np.arange(10), 2),
    'y': vals
})

alt.Chart(df).mark_bar(width=20).encode(
    x='cat',
    y='y',
    color='cat',
    column='x'
).configure_view(strokeWidth=0)

是否可以在保持水平网格线的同时保持每组之间的space?

您可以将小平面间距与调整比例域结合起来执行如下操作:

import pandas as pd
import numpy as np
import altair as alt

vals = np.concatenate(((np.arange(10) ** 2) / 9, np.arange(10)))
df = pd.DataFrame({
    'cat': np.repeat(['a', 'b'], 10),
    'x': np.tile(np.arange(10), 2),
    'y': vals
})

alt.Chart(df).mark_bar(width=20).encode(
    x=alt.X('cat', scale=alt.Scale(domain=['', 'a', 'b'])),
    y='y',
    color='cat',
).facet(
    'x', spacing=0
).configure_view(
    strokeWidth=0
)