在不同的地块中绘制多个熊猫自相关图

Question

我的问题在某种程度上与this one有关。我有一个Pandas DataFrame，我想单独绘制value的自相关函数，category中的每一项。下面是我尝试过的，它将所有的自相关函数绘制在同一张图上。如何分别打印它们并控制打印大小？

# Import libraries
import pandas as pd
from pandas.plotting import autocorrelation_plot

# Create DataFrame
df = pd.DataFrame({
    'category': ['sav','sav','sav','sav','sav','check','check','check','check','check','cd','cd','cd','cd','cd'],
    'value': [1.2,1.3,1.5,1.7,1.8, 10,13,17,20,25, 7,8,8.5,9,9.3]
})

# Loop through for each item in category and plot autocorrelation function
for cat in df['category'].unique():
    s = df[df['category']==cat]['value']
    s = s.diff().iloc[1:] #First order difference to de-trend
    ax = autocorrelation_plot(s)

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Answer 1

一种简单的方法是在每次迭代后使用plt.show()强制呈现

# Loop through for each item in category and plot autocorrelation function
for cat in df['category'].unique():

    # create new figure, play with size
    plt.figure(figsize=(10,6))
    s = df[df['category']==cat]['value']
    s = s.diff().iloc[1:] #First order difference to de-trend
    ax = autocorrelation_plot(s)
    plt.show()  # here

此外，使用groupby还可以简化语法

for cat, data in df.groupby('category')['value']:
    plt.figure(figsize=(10,6))

    autocorrelation_plot(data.diff().iloc[1:])

    plt.title(cat)
    plt.show()