如何将整个数据框行添加为散点图注释

Question

我正在散点图上绘制 Pandas DataFrame 的两列，我希望每个点都显示 DataFrame 的所有行值。我看过 this post, and tried to do something similar with mplcursors:

import pandas as pd
from datetime import date, datetime, time, timedelta
import numpy as np
import matplotlib.pyplot as plt
from mplcursors import cursor

df = pd.DataFrame()
df['datetime'] = pd.date_range(start='2016-01-01', end='2016-01-14', freq='30T')
#df = df.set_index('datetime')
df['x1'] = np.random.randint(-30, 30, size=len(df))
df['x2'] = np.random.randint(-30, 20, size=len(df))
df['x3'] = np.random.randint(-20, 30, size=len(df))
df['y1'] = np.random.randint(-100, 100, size=len(df))
df['y2'] = np.random.randint(-300, 200, size=len(df))
df['y3'] = np.random.randint(-200, 300, size=len(df))

def conditions(s):
    if (s['y1'] > 20) or (s['y3'] < 0):
        return 'group1'
    elif (s['x3'] < 20):
        return 'group2'
    elif (s['x2'] == 0):
        return 'group3'
    else:
        return 'group4'

df['category'] = df.apply(conditions, axis=1)

fig = plt.figure(figsize=(12,4))

ax1 = plt.subplot(121)
ax1.scatter(df.x1, df.y1, label='test1')
ax1.scatter(df.x2, df.y2, label='test2')
#cursor(hover=True)
ax1.set_xlabel('test1')
ax1.set_ylabel('test2')
ax1.legend(['test1','test2'])
cr1 = cursor(ax1,hover=True)
#ax1.annotation_names = df.columns.tolist()
cr1.connect("add", lambda x: x.annotation.set_text(df.columns.tolist()[x.target.index]))

ax2 = plt.subplot(122)
ax2.scatter(df.x1, df.y1, label='test1')
ax2.scatter(df.x3, df.y3, label='test3')
ax2.set_xlabel('test1')
ax2.set_ylabel('test3')
ax2.legend(['test1','test3'])
cr2 = cursor(ax2,hover=True)
#ax2.annotation_names = df.columns.tolist()
cr2.connect("add", lambda x: x.annotation.set_text(df.columns.tolist()[x.target.index]))

# save figure
import pickle
pickle.dump(fig, open('FigureObject.fig.pickle', 'wb'))
plt.show()

当我将鼠标悬停在一个点上时，我想看到一个包含（例如）的标签：

datetime = 2016-01-01 00:00:00 
x1 = 1 
x2 = -4 
x3 = 22 
y1 = -42 
y2 = -219 
y3 = -158    
category = group1

但是我得到了这种类型的错误：

cr2.connect("add", lambda x: x.annotation.set_text(df.columns.tolist()[x.target.index]))
IndexError: list index out of range

我该如何解决？

Answer 1

IndexError 的发生是因为 df.columns.tolist()[x.target.index]
- df.columns.tolist() 是 7 列的列表，然后由 [x.target.index].
df.iloc[x.target.index, :].to_dict() 将获取该点所需的行数据作为 dict
- A list comprehension 为每个 key value 对
- '\n'.join(...) 创建一个字符串，每列由 \n

cr1.connect("add", lambda x: x.annotation.set_text('\n'.join([f'{k}: {v}' for k, v in df.iloc[x.target.index, :].to_dict().items()])))

或者，使用 .to_string()

cr1.connect("add", lambda x: x.annotation.set_text(df.iloc[x.target.index, :].to_string()))

如何将整个数据框行添加为散点图注释

How to add entire dataframe row as scatter plot annotation

annotations

matplotlib

python-3.x

pandas

mplcursors