尝试检查这段代码:
# import section
import pandas as pd
import matplotlib.pyplot as plt
import matplotlib.dates as md
import numpy as np
from datetime import date
from itertools import product
# generate a dataframe like yours
date = [date(2020, m, d).strftime("%B %d") for m, d in product(range(1, 13, 1), range(1, 29, 1))]
value = np.abs(np.random.randn(len(date)))
data = pd.DataFrame({'date': date,
'value': value})
data.set_index('date', inplace = True)
# convert index from str to date
data.index = pd.to_datetime(data.index, format = '%B %d')
# plot
fig, ax = plt.subplots(1, 1, figsize = (16, 8))
ax.bar(data.index,
data['value'])
# formatting xaxis
ax.xaxis.set_major_locator(md.DayLocator(interval = 5))
ax.xaxis.set_major_formatter(md.DateFormatter('%B %d'))
plt.setp(ax.xaxis.get_majorticklabels(), rotation = 90)
ax.set_xlim([data.index[0], data.index[-1]])
plt.show()
这给了我这个情节:
我将数据帧的索引从字符串转换为日期,然后应用了我想要的 xaxis 格式ax.xaxis.set_major_locator
and ax.xaxis.set_major_formatter
方法。
为了绘制我使用的matplotlib
,但将这种方法转化为应该不难pylab
.
EDIT
如果您想要几天和几个月的单独刻度,您可以添加辅助轴(选中此example https://matplotlib.org/examples/axes_grid/demo_parasite_axes2.html)如这段代码所示:
# import section
import pandas as pd
import matplotlib.pyplot as plt
import matplotlib.dates as md
import numpy as np
from datetime import date
from itertools import product
from mpl_toolkits.axes_grid1 import host_subplot
import mpl_toolkits.axisartist as AA
# generate a dataframe like yours
date = [date(2020, m, d).strftime("%B %d") for m, d in product(range(1, 13, 1), range(1, 29, 1))]
value = np.abs(np.random.randn(len(date)))
data = pd.DataFrame({'date': date,
'value': value})
data.set_index('date', inplace = True)
# convert index from str to date
data.index = pd.to_datetime(data.index, format = '%B %d')
# prepare days and months axes
fig = plt.figure(figsize = (16, 8))
days = host_subplot(111, axes_class = AA.Axes, figure = fig)
plt.subplots_adjust(bottom = 0.1)
months = days.twiny()
# position months axis
offset = -20
new_fixed_axis = months.get_grid_helper().new_fixed_axis
months.axis['bottom'] = new_fixed_axis(loc = 'bottom',
axes = months,
offset = (0, offset))
months.axis['bottom'].toggle(all = True)
#plot
days.bar(data.index, data['value'])
# formatting days axis
days.xaxis.set_major_locator(md.DayLocator(interval = 10))
days.xaxis.set_major_formatter(md.DateFormatter('%d'))
plt.setp(days.xaxis.get_majorticklabels(), rotation = 0)
days.set_xlim([data.index[0], data.index[-1]])
# formatting months axis
months.xaxis.set_major_locator(md.MonthLocator())
months.xaxis.set_major_formatter(md.DateFormatter('%b'))
months.set_xlim([data.index[0], data.index[-1]])
plt.show()
产生这个图: