DataFrame.
expanding
Provide expanding transformations.
min_periods (int, default 1) –
number of observations in window required to have a value (Minimum) –
result is NA) ((otherwise) –
center (bool, default False) –
the labels at the center of the window. (Set) –
axis (int or str, default 0) –
a Window sub-classed for the particular operation
参见
rolling
Provides rolling window calculations.
ewm
Provides exponential weighted functions.
提示
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.
center=True
实际案例
>>> import numpy as np >>> import mars.dataframe as md >>> df = md.DataFrame({'B': [0, 1, 2, np.nan, 4]}) >>> df.execute() B 0 0.0 1 1.0 2 2.0 3 NaN 4 4.0 >>> df.expanding(2).sum().execute() B 0 NaN 1 1.0 2 3.0 3 3.0 4 7.0