qolmat.imputations.imputers.ImputerLOCF

class qolmat.imputations.imputers.ImputerLOCF(groups: Tuple[str, ...] = ())

LOCF imputer.

It imputes by the last available value of the column. Relevant for time series. If the first observations are missing, it is imputed by a NOCB

Parameters

groups: Tuple[str, …]

List of column names to group by, by default []

Examples

>>> import numpy as np
>>> import pandas as pd
>>> from qolmat.imputations import imputers
>>> imputer = imputers.ImputerLOCF()
>>> df = pd.DataFrame(
...     data=[
...         [1, 1, 1, 1],
...         [np.nan, np.nan, np.nan, np.nan],
...         [1, 2, 2, 5],
...         [2, 2, 2, 2],
...     ],
...     columns=["var1", "var2", "var3", "var4"],
... )
>>> imputer.fit_transform(df)
   var1  var2  var3  var4
0   1.0   1.0   1.0   1.0
1   1.0   1.0   1.0   1.0
2   1.0   2.0   2.0   5.0
3   2.0   2.0   2.0   2.0

__init__(groups: Tuple[str, ...] = ()) → None