我想把它从一条回归线变成一条曲线。也要让线到达图表的任意一侧。这是我的密码：

import seaborn as sns
import matplotlib.pyplot as plt
import pandas as pd
import numpy as np

data = {'Days':  [5, 10, 15, 20],
        'Impact': [33.7561, 30.6281, 29.5748, 29.0482]
        }

a = pd.DataFrame (data, columns = ['Days','Impact'])

print (a)

ax = sns.barplot(data=a, x='Days', y='Impact', color='lightblue' )

# put bars in background:

for c in ax.patches:
    c.set_zorder(0)

# plot regplot with numbers 0,..,len(a) as x value

ax = sns.regplot(x=np.arange(0,len(a)), y=a['Impact'], marker="+")
sns.despine(offset=10, trim=False)
ax.set_ylabel("")
ax.set_xticklabels(['5', '10','15','20'])
plt.show()

或者，我更喜欢在matplotlib中以散点图而不是条形图的形式进行。下面是excel中的一个示例，但理想情况是使曲线至少稍微超出外部标记。

有人能帮忙吗？