用Python的matplotlib在x轴上绘制日期(Plotting dates on the x

用Python的matplotlib在x轴上绘制日期(Plotting dates on the x-axis with Python's matplotlib)

我试图根据日期绘制信息。 我有一个格式为“01/02/1991”的日期列表。

我通过执行以下操作来转换它们：

x = parser.parse(date).strftime('%Y%m%d'))

这给了19910102

然后我尝试使用num2date

import matplotlib.dates as dates new_x = dates.num2date(x)

绘图：

plt.plot_date(new_x, other_data, fmt="bo", tz=None, xdate=True)

但是我得到一个错误。 它说“ValueError：年度超出范围”。 任何解决方案

I am trying to plot information against dates. I have a list of dates in the format "01/02/1991".

I converted them by doing the following:

x = parser.parse(date).strftime('%Y%m%d'))

which gives 19910102

Then I tried to use num2date

import matplotlib.dates as dates new_x = dates.num2date(x)

Plotting:

plt.plot_date(new_x, other_data, fmt="bo", tz=None, xdate=True)

But I get an error. It says "ValueError: year is out of range". Any solutions?

最满意答案

正如@KyssTao一直在说的， help(dates.num2date)表示x必须是一个浮点数，给出0001-01-01以后的天数加上1。 因此， 19910102不是1991年1月2日，因为如果你从0001-01-01算起19910101天，你会得到54513年或类似年份（除以365.25，一年中的天数）。

改为使用datestr2num （请参阅help(dates.datestr2num) ）：

new_x = dates.datestr2num(date) # where date is '01/02/1991'

As @KyssTao has been saying, help(dates.num2date) says that the x has to be a float giving the number of days since 0001-01-01 plus one. Hence, 19910102 is not 2/Jan/1991, because if you counted 19910101 days from 0001-01-01 you'd get something in the year 54513 or similar (divide by 365.25, number of days in a year).

Use datestr2num instead (see help(dates.datestr2num)):

new_x = dates.datestr2num(date) # where date is '01/02/1991'