Matplotlib 显示 x 轴标签不完整；如何防止重叠？

Question

我已经编写了显示 MACD 指标图的代码。我在这里做了什么：import pandas as pdimport numpy as npimport matplotlib.pyplot as pltimport matplotlib.dates as mdatesdf = pd.read_csv(#stock_chart)df = df.rename(columns={"<DTYYYYMMDD>":"Date"})df['Date'] = pd.to_datetime(df['Date'].astype(str), format="%Y%m%d")print(df.head())#seting index for graphdf = df.set_index(df['Date'].values)print(df.head())我的数据框的头部是：#MacdS_term = 12L_term = 26s_ema = df.close.ewm(span=S_term, adjust=False).mean()l_ema = df.close.ewm(span=L_term, adjust=False).mean()#calculate MACDmacd = s_ema - l_emasignal_term = 9signal_line = macd.ewm(span= signal_term, adjust=False).mean()#plot the graphsplt.figure(figsize=(100,10)) #width = 12.2in, height = 4.5plt.plot(df.index, macd, label='macd', color = 'red')plt.plot(df.index, signal_line, label='Signal Line', color='blue')plt.tight_layout()plt.xticks(rotation=0)plt.legend(loc='upper left')plt.show()最后，我得到了这个：不管怎样，问题是尽管行索引标签是这样的：2020-08-19 or "%Y%m%d"图形标签不完整，如果我重新排序，数据就会相互重叠。我需要做什么 ？

Answer 1

您可以使用Date locators和Date formatters。

import numpy

import matplotlib.pyplot as plt

import matplotlib.dates as mdates

import pandas

N = 192

numpy.random.seed(N)

dates = pandas.date_range('1/1/2004', periods=N, freq='m')

df = pandas.DataFrame(

    data=numpy.random.randn(N), 

    index=dates,

    columns=['A']

)

fig, ax = plt.subplots()

ax.plot(df.index, df['A'])

ax.xaxis.set_major_locator(mdates.YearLocator())

ax.xaxis.set_major_formatter(mdates.DateFormatter('%Y'))

fig.autofmt_xdate()

plt.show()

interval是每次迭代之间的间隔。例如，如果interval=2，标记每两次出现一次。

import numpy

import matplotlib.pyplot as plt

import matplotlib.dates as mdates

import pandas

N = 192

numpy.random.seed(N)

dates = pandas.date_range('1/1/2004', periods=N, freq='m')

df = pandas.DataFrame(

    data=numpy.random.randn(N), 

    index=dates,

    columns=['A']

)

fig, ax = plt.subplots()

ax.plot(df.index, df['A'])

ax.xaxis.set_major_locator(mdates.MonthLocator(interval=5))

ax.xaxis.set_major_formatter(mdates.DateFormatter('%Y-%m'))

fig.autofmt_xdate()

plt.show()