改变seaborn factorplot中一条线的alpha

Question

import seaborn as sns
sns.set(style="ticks")
exercise = sns.load_dataset("exercise")
g = sns.factorplot(x="time", y="pulse", hue="kind", data=exercise)

在上面的代码中，如何将rest线更改为 0.5 的 alpha？

Answer 1

FacetGrid使用get_children()方法找到合适的轴对象并为线条和标记设置 alpha。要更改图例（g._legend对象）中的标记属性，请找到合适的元素legendHandles并应用set_alpha()方法：

import seaborn as sns
import matplotlib.pylab as plt

sns.set(style="ticks")
exercise = sns.load_dataset("exercise")
g = sns.factorplot(x="time", y="pulse", hue="kind", data=exercise)

# set alpha for marker (index 0) and for the rest line (indeces 3-6) 
plt.setp([g.ax.get_children()[0],g.ax.get_children()[3:7]],alpha=.5)

# modify marker in legend box
g._legend.legendHandles[0].set_alpha(.5)

plt.show()