在Pandas中用指数移动平均值创建一个新列

Question

编辑：此问题已被标记为与how to find exponential weighted moving average using dataframe.ewma?重复

但尝试使用：

df1['ema'] = df1['values'].ewm(span=5)

如提到的帖子中所述，

会出现以下错误：

NotImplementedError                       Traceback (most recent call last)
<ipython-input-8-5c535ef97a6c> in <module>
     29 
     30 df1 = pd.DataFrame({'values': col_values})
---> 31 df1['ema'] = df1['values'].ewm(span=5)
…
c:\users\user\appdata\local\programs\python\python37-32\lib\site-packages\pandas\core\window.py in __iter__(self)
    173     def __iter__(self):
    174         url = 'https://github.com/pandas-dev/pandas/issues/11704'
--> 175         raise NotImplementedError('See issue #11704 {url}'.format(url=url))
    176 
    177     def _get_index(self, index=None):

NotImplementedError: See issue #11704 https://github.com/pandas-dev/pandas/issues/11704

---

我试图在Pandas数据框中创建一个新列，其中包含名为“值”的列的指数移动平均值。

我尝试了以下方法：

import pandas as pd
import numpy as np

col_values = [-10.5,
 15.899999999999864,
 41.5,
 65.19999999999993,
 86.5,
 96.10000000000014,
 106.30000000000007,
 110.5,
 138.10000000000014,
 104.50000000000034,
 115.30000000000041,
 122.80000000000041,
 130.60000000000048,
 146.50000000000034,
 148.60000000000048,
 173.00000000000057,
 160.1000000000007,
 185.00000000000057,
 214.40000000000066,
 241.80000000000052,
 269.8000000000005,
 286.6000000000006,
 311.2000000000005,
 323.80000000000064,
 308.50000000000057]

df1 = pd.DataFrame({'values': col_values})
df1['ema'] = df1['values'].ewma(min_period=5)
df1.head(50)

但出现以下错误：

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-5-d6630f195441> in <module>
     29 
     30 df1 = pd.DataFrame({'values': col_values})
---> 31 df1['ema'] = df1['values'].ewma(min_period=5)
     32 df1.head(50)

c:\users\user\appdata\local\programs\python\python37-32\lib\site-packages\pandas\core\generic.py in __getattr__(self, name)
   5065             if self._info_axis._can_hold_identifiers_and_holds_name(name):
   5066                 return self[name]
-> 5067             return object.__getattribute__(self, name)
   5068 
   5069     def __setattr__(self, name, value):

AttributeError: 'Series' object has no attribute 'ewma'