带有日期时间基础的python plot stem

Question

我希望使用基于日期时间的 matplotlib 绘制一个主干。但似乎发生了错误:示例代码:

import matplotlib.pyplot as plt
from dateutil import parser

x = parser.parse("2013-9-28 11:00:00")
y = 100

x1 = parser.parse("2013-9-28 12:00:00")
y1 = 200

plt.stem([x,x1],[y,y1],"*-")

错误信息:

    318 
    319     """
--> 320     return array(a, dtype, copy=False, order=order)
    321 
    322 def asanyarray(a, dtype=None, order=None):

TypeError: float() argument must be a string or a number

Answer 1

好像stem x轴只接受float，所以你可以把你的日期转换成timestamp(float)然后绘图。要在轴上显示日期，请使用 .xticks()。这是一个例子:

import numpy as np
import matplotlib.pyplot as plt
from time import mktime
from datetime import datetime

ticks = [ "2013-9-28 11:00:00.234", "2013-9-28 11:10:00.123", "2013-9-28 11:40:00.654", "2013-9-28 11:50:00.341", "2013-9-28 12:00:00.773"]
y = np.array([10, 12, 9, 15, 11])
x = [mktime(datetime.strptime(i, "%Y-%m-%d %H:%M:%S.%f").timetuple()) for i in ticks]

plt.stem(x,y)
plt.xticks(x, ticks)
plt.show()