Python 如何用matplotlib绘制x轴上的时间

发布于11月13日

按照给定HERE的示例，我想创建一个只显示x轴上的时间而不是日期的曲线图.因此，我将示例代码修改为以下代码:

from datetime import datetime as dt
from matplotlib import pyplot as plt, dates as mdates

plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True

dates = ["01/02/2020 10:00", "01/02/2020 10:05", "01/02/2020 10:10"]
x_values = [dt.strptime(d, "%m/%d/%Y %H:%M").date() for d in dates]
y_values = [1, 2, 3]
ax = plt.gca()

formatter = mdates.DateFormatter("%H:%M")
ax.xaxis.set_major_formatter(formatter)
locator = mdates.HourLocator()
ax.xaxis.set_major_locator(locator)
plt.plot(x_values, y_values)

plt.show()

但我得到的不是10:00到10:10的时间范围，而是:

怎么啦？

推荐答案

我认为有两个问题是，当你将.date()链接到.strptime(...)时，时间信息被丢弃了，第二，使用了HourLocator而不是MinuteLocator.

from datetime import datetime as dt
from matplotlib import pyplot as plt, dates as mdates

plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True

dates = ["01/02/2020 10:00", "01/02/2020 10:05", "01/02/2020 10:10"]
x_values = [dt.strptime(d, "%m/%d/%Y %H:%M") for d in dates]
y_values = [1, 2, 3]
ax = plt.gca()

formatter = mdates.DateFormatter("%H:%M")
ax.xaxis.set_major_formatter(formatter)

#Comment out to show fewer minute ticks
locator = mdates.MinuteLocator()
ax.xaxis.set_major_locator(locator)

plt.plot(x_values, y_values, 'o-');