Question

例如，我有一个数据框，希望x轴显示为APR-2018。 ax.format_xdata行无法解决问题。

import datetime as dt
import pandas as pd
import time
import matplotlib.pyplot as plt
import matplotlib.dates as mdates

data = {("IVOG",1493510400000):{"Adj_Close":119.2136,"MA(3)":119.2136,"EWMA(3)":119.2136},
        ("IVOG",1496188800000):{"Adj_Close":120.8236,"MA(3)":120.0186,"EWMA(3)":120.0454},
        ("IVOG",1498780800000):{"Adj_Close":120.2736,"MA(3)":120.1036,"EWMA(3)":120.1266},
        ("IVOG",1501459200000):{"Adj_Close":121.7836,"MA(3)":120.5236,"EWMA(3)":120.5832},
        ("IVOG",1504137600000):{"Adj_Close":120.3536,"MA(3)":120.4896,"EWMA(3)":120.5309},
        ("IVOG",1506729600000):{"Adj_Close":124.3336,"MA(3)":121.1303,"EWMA(3)":121.2749}}

df=pd.DataFrame.from_dict(data, orient = 'index')
print(df)
ax = plt.gca()      # get current axis
df.plot(kind='line',y='Adj_Close', ax=ax)
df.plot(kind='line',y='MA(3)',ax=ax)
df.plot(kind='line',y='EWMA(3)', color='green', ax=ax)
print(df.index[0][1])
ax.format_xdata = mdates.DateFormatter('%b-%Y')     # Trying to get APR-2018
plt.xlabel(df.index[0][0])     # Trying to Get the Ticker
_=plt.grid()
_=plt.xticks(rotation=90)
plt.show()

第二个索引应该只是日期，而不是时间，但是它错误地绘制如下图：Incorrect Plot

Answer 1

这应该可以解决问题。当然，有“更漂亮”的方法，但是我已经尝试过这样做，以便您可以使数据和原始数据帧保持与问题中的原始数据帧尽可能接近。

注释后编辑：因此，只需创建一个新列，并以所需的日期格式设置日期即可。然后使用 set_xticklabels（）将该列传递给您以设置刻度。另外，您可能希望删除默认的plt.xlabel（否则，在xticks下方将有索引名称）。

import datetime as dt
import pandas as pd
import time
import matplotlib.pyplot as plt
import matplotlib.dates as mdates

# the first part of your code is the same
data = {("IVOG",1493510400000):{"Adj_Close":119.2136,"MA(3)":119.2136,"EWMA(3)":119.2136},
    ("IVOG",1496188800000):{"Adj_Close":120.8236,"MA(3)":120.0186,"EWMA(3)":120.0454},
    ("IVOG",1498780800000):{"Adj_Close":120.2736,"MA(3)":120.1036,"EWMA(3)":120.1266},
    ("IVOG",1501459200000):{"Adj_Close":121.7836,"MA(3)":120.5236,"EWMA(3)":120.5832},
    ("IVOG",1504137600000):{"Adj_Close":120.3536,"MA(3)":120.4896,"EWMA(3)":120.5309},
    ("IVOG",1506729600000):{"Adj_Close":124.3336,"MA(3)":121.1303,"EWMA(3)":121.2749}}

df=pd.DataFrame.from_dict(data, orient = 'index')

# first let's give a name to the indexes
df.index.names = ['ivog', 'timestamp']

# then create a new column with a datetime object
# (formatted to microseconds as your data seems to be)
df['date'] = pd.to_datetime(df.index.levels[1], 
unit='ms')

# now let's change the date to the format you want
df['date'] = df['date'].apply(lambda x: x.strftime("%Y %B"))


print(df)

# plot the data just like you were doing
ax = plt.gca()      # get current axis
df.plot(kind='line',y='Adj_Close', ax=ax)
df.plot(kind='line',y='MA(3)',ax=ax)
df.plot(kind='line',y='EWMA(3)', color='green', ax=ax)

# Now the x-axis label should be what you wished for
ax.set_xticklabels(df['date'])
plt.xlabel('Your x axis label') 
plt.ylabel('Your y axis label')
plt.title('My Awseome Plot')
plt.xticks(rotation=45)

在x轴上绘制格式为月年的熊猫数据框索引

1 个答案: