Seaborn小提琴图透明度

Question

我希望在 seaborn.violinplot 中有越来越透明的小提琴。我尝试了以下方法：

import seaborn as sns

tips = sns.load_dataset("tips")

ax = sns.violinplot(x="day", y="total_bill", data=tips, color='r', alpha=[0.8, 0.6, 0.4, 0.2])

Which does not result in the desired output:

Answer 1

Found this thread looking to change alpha values in general for violin plots, it seems you need to access matplotlib.PolyColections from your ax to even be able to set the alpha values, but since you need to access them anyways, you might as well set alpha values individually (at least in your case since you want individual alpha values).

From my understanding, ax.collections contain both matplotlib.PolyCollections and matplotlib.PathCollections, you only need the PolyCollections, so I did the following and it seems to work:

ax = sns.violinplot(x = 'day', y = 'total_bill', data = tips, color = 'r')
for violin, alpha in zip(ax.collections[::2], [0.8,0.6,0.4,0.2]):
    violin.set_alpha(alpha)

ax.collections[::2] ignores PathCollections, as ax.collections comes in format of [PolyCollection1, PathCollection1, PolyCollection2, PathCollection2, ...]

Output:

Answer 2

按照同一个线程更新。

更简单的答案是：

plt.setp(ax.collections, alpha=.3)