Matplotlib DateFormatter用于轴标签不工作 [英] Matplotlib DateFormatter for axis label not working

问题描述

我正在调整x轴的日期刻度标签的格式，以便仅显示年份和月份值。从我在网上找到的，我必须使用mdates.DateFormatter，但是它根本就没有使用我现在的代码。任何人看到问题在哪里？ （日期是熊猫DF的索引）

I'm trying to adjust the formatting of the date tick labels of the x-axis so that it only shows the Year and Month values. From what I've found online, I have to use mdates.DateFormatter, but it's not taking effect at all with my current code as is. Anyone see where the issue is? (the dates are the index of the pandas DF)

import matplotlib.dates as mdates
import matplotlib.pyplot as plt
import pandas as pd 

fig = plt.figure(figsize = (10,6))
ax = fig.add_subplot(111)

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

basicDF['some_column'].plot(ax=ax, kind='bar', rot=75)

ax.xaxis_date()

谢谢你们！

可重现场景代码 / p>

Reproducible scenario code:

import numpy as np
import matplotlib.dates as mdates
import matplotlib.pyplot as plt
import pandas as pd 

rng = pd.date_range('1/1/2014', periods=20, freq='m')

blah = pd.DataFrame(data = np.random.randn(len(rng)), index=rng)

fig = plt.figure(figsize = (10,6))
ax = fig.add_subplot(111)

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

blah.plot(ax=ax, kind='bar')

ax.xaxis_date()

仍然无法获得仅显示年和月的...

Still can't get just the year and month to show up...

推荐答案

pandas只适用于自定义日期格式。

pandas just doesn't work well with custom date-time formats.

您需要只需在这样的情况下使用raw matplotlib。

You need to just use raw matplotlib in cases like this.

import numpy
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import pandas

N = 20
numpy.random.seed(N)

dates = pandas.date_range('1/1/2014', periods=N, freq='m')
df = pandas.DataFrame(
    data=numpy.random.randn(N), 
    index=dates,
    columns=['A']
)

fig, ax = plt.subplots(figsize=(10, 6))
ax.xaxis.set_major_formatter(mdates.DateFormatter('%Y-%m'))
ax.bar(df.index, df['A'], width=25, align='center')

这就是我：

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