向 seaborn 箱线图添加自定义图例

Question

我用seaborn生成了M个方法的N个箱线图，然后我用相同的颜色给每个方法的箱线图上色。我现在只想添加一个图例，以不同颜色显示 M 方法的名称（例如 red_line 方法 A、blue_line 方法 B 等等）。任何快速的方法来做到这一点？

bplot = sns.boxplot(data=[d for d in data])   
colors = ["red", "green", "blue"]    
color_counter = 0
for i in range(len(data)-len(c)): 
    mybox = bplot.artists[i]
    mybox.set_facecolor(colors[color_counter])
    color_counter = color_counter + 1
    if color_counter == len(methods): 
        color_counter=0   
# COMMENTING NEXT CODE BLOCK AS IT OUTPUTS TEXT ASSOCIATED TO GRAY LINES (I want them to be colored instead) 
# leg = plt.legend(labels=[method for method in methods])
# for legobj in leg.legendHandles:
#     legobj.set_linewidth(12.0)
# params = {'legend.fontsize': 80}
# plt.rcParams.update(params)
plt.legend()  
plt.title('Title')
plt.show()

Answer 1

Matplotlib 允许您创建自定义图例，其中几乎包含您想要的任何内容。

见https://matplotlib.org/3.2.1/gallery/text_labels_and_annotations/custom_legends.html

对于你的情况，你会创建类似

的东西

from matplotlib.lines import Line2D
import matplotlib.pyplot as plt

legend_elements = [Line2D([0], [0], color='red', lw=4, label='Method 1'),
Line2D([0], [0], color='green', lw=4, label='Method 2'),
Line2D([0], [0], color='blue', lw=4, label='Method 3')]

# Create the figure
fig, ax = plt.subplots()
ax.legend(handles=legend_elements, loc='center')

plt.show()

向 seaborn 箱线图添加自定义图例

Add custom legend to seaborn boxplots

python

matplotlib

boxplot

seaborn