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当使用花车接近无穷大时,熊猫滚动时发生错误。我在这里显示一个示例:pandas.DataFrame.rolling不适用于大型花车
import pandas as pd
series = pd.Series(1.,index = pd.date_range('2015-01-01', periods=6))
series[series.index[2]] = 1e19
series
2015-01-01 1.000000e+00
2015-01-02 1.000000e+00
2015-01-03 1.000000e+19
2015-01-04 1.000000e+00
2015-01-05 1.000000e+00
2015-01-06 1.000000e+00
Freq: D, dtype: float64
series.rolling('2D', closed = 'left').mean()
2015-01-01 NaN
2015-01-02 1.000000e+00
2015-01-03 1.000000e+00
2015-01-04 5.000000e+18
2015-01-05 5.000000e+18
2015-01-06 5.000000e-01
Freq: D, dtype: float64
最后一位的答案应该是1!但是它是0.5。为什么在使用大数字时会滚动?与较小的浮动相同的示例:
series[series.index[2]] = 1e9
series.rolling('2D', closed = 'left').mean()
2015-01-01 NaN
2015-01-02 1.0
2015-01-03 1.0
2015-01-04 500000000.5
2015-01-05 500000000.5
2015-01-06 1.0
Freq: D, dtype: float64
用.sum()进行测试,以查看发生了什么。最后一个条目最终为1,而它应该为2.将1e19更改为较小的数字可以解决问题,即使它位于滚动窗口之外也不会起作用。非常奇怪的行为!也许在[pandas github](https://github.com/pandas-dev/pandas/issues)上提交问题单? –