标签：util sel frequency void core which iter poi github
DataFrame.rolling(self, window, min_periods=None, center=False, win_type=None, on=None, axis=0, closed=None)[source]¶
Provide rolling window calculations.
New in version 0.18.0.
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Notes
By default, the result is set to the right edge of the window. This can be changed to the center of the window by setting center=True.
To learn more about the offsets & frequency strings, please see this link.
The recognized win_types are:
boxcartriangblackmanhammingbartlettparzenbohmanblackmanharrisnuttallbarthannkaiser (needs beta)gaussian (needs std)general_gaussian (needs power, width)slepian (needs width)exponential (needs tau), center is set to None.If win_type=None all points are evenly weighted. To learn more about different window types see scipy.signal window functions.
Examples：
>>> df = pd.DataFrame({‘B‘: [0, 1, 2, np.nan, 4]})
>>> df
B
0 0.0
1 1.0
2 2.0
3 NaN
4 4.0
Rolling sum with a window length of 2, using the ‘triang’ window type.
>>> df.rolling(2, win_type=‘triang‘).sum()
B
0 NaN
1 0.5
2 1.5
3 NaN
4 NaN
Rolling sum with a window length of 2, min_periods defaults to the window length.
>>> df.rolling(2).sum()
B
0 NaN
1 1.0
2 3.0
3 NaN
4 NaN
Same as above, but explicitly set the min_periods
>>> df.rolling(2, min_periods=1).sum()
B
0 0.0
1 1.0
2 3.0
3 2.0
4 4.0
A ragged (meaning not-a-regular frequency), time-indexed DataFrame
>>> df = pd.DataFrame({‘B‘: [0, 1, 2, np.nan, 4]},
... index = [pd.Timestamp(‘20130101 09:00:00‘),
... pd.Timestamp(‘20130101 09:00:02‘),
... pd.Timestamp(‘20130101 09:00:03‘),
... pd.Timestamp(‘20130101 09:00:05‘),
... pd.Timestamp(‘20130101 09:00:06‘)])
>>> df
B
2013-01-01 09:00:00 0.0
2013-01-01 09:00:02 1.0
2013-01-01 09:00:03 2.0
2013-01-01 09:00:05 NaN
2013-01-01 09:00:06 4.0
Contrasting to an integer rolling window, this will roll a variable length window corresponding to the time period. The default for min_periods is 1.
>>> df.rolling(‘2s‘).sum()
B
2013-01-01 09:00:00 0.0
2013-01-01 09:00:02 1.0
2013-01-01 09:00:03 3.0
2013-01-01 09:00:05 NaN
2013-01-01 09:00:06 4.0
标签：util sel frequency void core which iter poi github
原文地址：https://www.cnblogs.com/zjuhaohaoxuexi/p/11919269.html
