cross_validate#

skrub.cross_validate(pipeline, environment, *, keep_subsampling=False, **kwargs)[source]#

Cross-validate a pipeline built from an expression.

This runs cross-validation from a pipeline that was built from a skrub expression with .skb.get_pipeline(), .skb.get_grid_search() or .skb.get_randomized_search().

It is useful to run nested cross-validation of a grid search or randomized search.

Parameters:

pipelineskrub pipeline: A pipeline generated from a skrub expression.
environmentdict: Bindings for variables contained in the expression.
keep_subsamplingbool, default=False: If True, and if subsampling has been configured (see Expr.skb.subsample()), use a subsample of the data. By default subsampling is not applied and all the data is used.
kwargsdict: All other named arguments are forwarded to sklearn.model_selection.cross_validate(), except that scikit-learn’s return_estimator parameter is named return_pipeline here.

Returns:

dict: Cross-validation results.

See also

sklearn.model_selection.cross_validate(): Evaluate metric(s) by cross-validation and also record fit/score times.
skrub.Expr.skb.get_pipeline(): Get a skrub pipeline for this expression.
skrub.Expr.skb.get_grid_search(): Find the best parameters with grid search.
skrub.Expr.skb.get_randomized_search(): Find the best parameters with grid search.

Examples

>>> from sklearn.datasets import make_classification
>>> from sklearn.linear_model import LogisticRegression
>>> import skrub

>>> X_a, y_a = make_classification(random_state=0)
>>> X, y = skrub.X(X_a), skrub.y(y_a)
>>> log_reg = LogisticRegression(
...     **skrub.choose_float(0.01, 1.0, log=True, name="C")
... )
>>> pred = X.skb.apply(log_reg, y=y)
>>> search = pred.skb.get_randomized_search(random_state=0)
>>> skrub.cross_validate(search, pred.skb.get_data())['test_score']
0    0.75
1    0.90
2    0.95
3    0.75
4    0.85
Name: test_score, dtype: float64

cross_validate#

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