Binary indicators for missing values.
Note that this component typically should not be used in a vanilla :class:`Pipeline` consisting of transformers and a classifier, but rather could be added using a :class:`FeatureUnion` or :class:`ColumnTransformer`.
Read more in the :ref:`User Guide <impute>`.
Parameters ---------- missing_values : number, string, np.nan (default) or None The placeholder for the missing values. All occurrences of `missing_values` will be indicated (True in the output array), the other values will be marked as False.
features : str, default=None Whether the imputer mask should represent all or a subset of features.
- If "missing-only" (default), the imputer mask will only represent features containing missing values during fit time.
- If "all", the imputer mask will represent all features.
sparse : boolean or "auto", default=None Whether the imputer mask format should be sparse or dense.
- If "auto" (default), the imputer mask will be of same type as input.
- If True, the imputer mask will be a sparse matrix.
- If False, the imputer mask will be a numpy array.
error_on_new : boolean, default=None If True (default), transform will raise an error when there are features with missing values in transform that have no missing values in fit. This is applicable only when ``features="missing-only"``.
Attributes ---------- features_ : ndarray, shape (n_missing_features,) or (n_features,) The features indices which will be returned when calling ``transform``. They are computed during ``fit``. For ``features='all'``, it is to ``range(n_features)``.
Examples -------- >>> import numpy as np >>> from sklearn.impute import MissingIndicator >>> X1 = np.array([np.nan, 1, 3],
... [4, 0, np.nan],
... [8, 1, 0]
) >>> X2 = np.array([5, 1, np.nan],
... [np.nan, 2, 3],
... [2, 4, 0]
) >>> indicator = MissingIndicator() >>> indicator.fit(X1) MissingIndicator() >>> X2_tr = indicator.transform(X2) >>> X2_tr array([False, True],
[ True, False],
[False, False]
)