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在Matplotlib中绘制不同颜色的图形

graph dataframe pandas python

user98235 · 技术社区 · 8 年前

我有下表。

  Date       Score
11-01-02      40
11-01-03      47
11-01-04      41
11-01-05      35
11-01-06      52
11-01-07      47
11-01-08      45
11-01-09      43
11-01-10      40
11-01-11      41
11-01-12      41
11-01-13      49
11-01-14      40
11-01-15      40

我把它作为python中的pandas文件来读,我想把它画成一个线图,这样2011/01/08之前的分数都是黄色的,而2011/01/08或之后的分数都是红色的。

在python中是可能的吗?我知道在R语言中怎么做,但我不确定熊猫是否有类似的功能。

2 回复 | 直到 8 年前

Anton vBR 8 年前

import pandas as pd
import matplotlib.pyplot as plt

csvdata = '''\
Date          Score
11-01-02      40
11-01-03      47
11-01-04      41
11-01-05      35
11-01-06      52
11-01-07      47
11-01-08      45
11-01-09      43
11-01-10      40
11-01-11      41
11-01-12      41
11-01-13      49
11-01-14      40
11-01-15      40'''

# Recreate data and convert Date to datetime
fileobj = pd.compat.StringIO(csvdata)
df = pd.read_csv(fileobj, sep='\s+')
df['Date'] = pd.to_datetime(df['Date'], yearfirst=True)

# Based on the date provided by OP, either RED or YELLOW to col Color
cond = df.Date >= '2011-01-08'
df['Color'] = np.where(cond, 'RED', 'YELLOW')

# Create the frame 
fig, ax = plt.subplots(figsize=(8,6))

# Fill the frame with data (note: missing datapoint!)
for color, dfx in df.groupby('Color'):
   dfx.plot(x='Date', y='Score', color=color, ax=ax) 

# The workaround --> does not feel reliable for consistant use though.
m1 = df['Date'].between('2011-01-07', '2011-01-08')
df[m1].plot(x='Date',y='Score', color=df['Color'], ax=ax)

plt.show()