python – 在分组后使用mean和std绘制错误栏

发布时间：2020-12-20 11:48:25 所属栏目：Python 来源：网络整理

导读：我有以下数据帧： mean stdinsert quality 0.0 good 0.009905 0.0036620.1 good 0.450190 0.281895 poor 0.376818 0.3068060.2 good 0.801856 0.243288 poor 0.643859 0.3223780.3 good 0.833235 0.172025 poor 0.698972 0.2632660.4 good 0.842288 0.141925

我有以下数据帧：

mean       std
insert quality                    
0.0    good     0.009905  0.003662
0.1    good     0.450190  0.281895
       poor     0.376818  0.306806
0.2    good     0.801856  0.243288
       poor     0.643859  0.322378
0.3    good     0.833235  0.172025
       poor     0.698972  0.263266
0.4    good     0.842288  0.141925
       poor     0.706708  0.241269
0.5    good     0.853634  0.118604
       poor     0.685716  0.208073
0.6    good     0.845496  0.118609
       poor     0.675907  0.207755
0.7    good     0.826335  0.133820
       poor     0.656934  0.222823
0.8    good     0.829707  0.130154
       poor     0.627111  0.213046
0.9    good     0.816636  0.137371
       poor     0.589331  0.232756
1.0    good     0.801211  0.147864
       poor     0.554589  0.245867

如果想要绘制2条曲线(点误差),使用索引列“插入”作为X轴并将两条曲线区分为“质量”[好,差],我该怎么办？它们也应该是不同的颜色.

我有点卡住,我制作了各种各样的情节.

解决方法

您可以循环遍历df.groupby(‘quality’)中的组,并在每个组上调用group.plot.

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

df = pd.DataFrame({
    'insert': [0.0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.0,1.0],'mean': [0.009905,0.45019,0.376818,0.801856,0.643859,0.833235,0.698972,0.842288,0.706708,0.853634,0.685716,0.845496,0.675907,0.826335,0.656934,0.829707,0.627111,0.816636,0.589331,0.801211,0.554589],'quality': ['good','good','poor','poor'],'std': [0.003662,0.281895,0.306806,0.243288,0.322378,0.172025,0.263266,0.141925,0.241269,0.118604,0.208073,0.118609,0.207755,0.13382,0.222823,0.130154,0.213046,0.137371,0.232756,0.147864,0.245867]})

fig,ax = plt.subplots()    # 1

for key,group in df.groupby('quality'):
    group.plot('insert','mean',yerr='std',label=key,ax=ax)   # 2

plt.show()

enter image description here

要使两个图显示在相同的轴上：

>创建自己的轴对象,ax.
>在每次调用group.plot时将ax参数设置为axes对象

它可能看起来像条形图更好：

# fill in missing data with 0,so the bar plots are aligned
df = df.pivot(index='insert',columns='quality').fillna(0).stack().reset_index()

colors = ['green','red']
positions = [0,1]

for group,color,pos in zip(df.groupby('quality'),colors,positions):
    key,group = group
    print(group)
    group.plot('insert',kind='bar',width=0.4,position=pos,color=color,alpha=0.5,ax=ax)

ax.set_xlim(-1,11)  
plt.show()

enter image description here

（编辑：李大同）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!