ArcsinTransformer#
- class feature_engine.transformation.ArcsinTransformer(variables=None)[source]#
The ArcsinTransformer() applies the arcsin transformation to numerical variables.
The arcsin transformation, also called arcsin square root transformation, or angular transformation, takes the form of arcsin(sqrt(x)) where x is a real number between 0 and 1.
The arcsin square root transformation helps in dealing with probabilities, percents, and proportions. It aims to stabilize the variance of the variable and return more evenly distributed (Gaussian looking) values.
The ArcsinTransformer() only works with numerical variables which values are between 0 and 1. If a variable contains values outside of this range, the transformer will raise an error.
A list of variables can be passed as an argument. Alternatively, the transformer will automatically select and transform all numerical variables.
More details in the User Guide.
- Parameters
- variables: list, default=None
The list of numerical variables to transform. If None, the transformer will automatically find and select all numerical variables.
- Attributes
- variables_:
The group of variables that will be transformed.
- feature_names_in_:
List with the names of features seen during
fit
.- n_features_in_:
The number of features in the train set used in fit.
Examples
>>> import numpy as np >>> import pandas as pd >>> from feature_engine.transformation import ArcsinTransformer >>> np.random.seed(42) >>> X = pd.DataFrame(dict(x = np.random.beta(1, 1, size = 100))) >>> ast = ArcsinTransformer() >>> ast.fit(X) >>> X = ast.transform(X) >>> X.head() x 0 0.785437 1 0.253389 2 0.144664 3 0.783236 4 0.650777
Methods
fit:
This transformer does not learn parameters.
fit_transform:
Fit to data, then transform it.
get_feature_names_out:
Get output feature names for transformation.
get_params:
Get parameters for this estimator.
set_params:
Set the parameters of this estimator.
inverse_transform:
Convert the data back to the original representation.
transform:
Apply the arcsin transformation.
- fit(X, y=None)[source]#
This transformer does not learn parameters.
- Parameters
- X: Pandas DataFrame of shape = [n_samples, n_features].
The training input samples. Can be the entire dataframe, not just the variables to transform.
- y: pandas Series, default=None
It is not needed in this transformer. You can pass y or None.
- fit_transform(X, y=None, **fit_params)[source]#
Fit to data, then transform it.
Fits transformer to
X
andy
with optional parametersfit_params
and returns a transformed version ofX
.- Parameters
- Xarray-like of shape (n_samples, n_features)
Input samples.
- yarray-like of shape (n_samples,) or (n_samples, n_outputs), default=None
Target values (None for unsupervised transformations).
- **fit_paramsdict
Additional fit parameters.
- Returns
- X_newndarray array of shape (n_samples, n_features_new)
Transformed array.
- get_feature_names_out(input_features=None)[source]#
Get output feature names for transformation. In other words, returns the variable names of transformed dataframe.
- Parameters
- input_featuresarray or list, default=None
This parameter exits only for compatibility with the Scikit-learn pipeline.
If
None
, thenfeature_names_in_
is used as feature names in.If an array or list, then
input_features
must matchfeature_names_in_
.
- Returns
- feature_names_out: list
Transformed feature names.
- get_params(deep=True)[source]#
Get parameters for this estimator.
- Parameters
- deepbool, default=True
If True, will return the parameters for this estimator and contained subobjects that are estimators.
- Returns
- paramsdict
Parameter names mapped to their values.
- inverse_transform(X)[source]#
Convert the data back to the original representation.
- Parameters
- X: Pandas DataFrame of shape = [n_samples, n_features]
The data to be transformed.
- Returns
- X_tr: pandas dataframe
The dataframe with the transformed variables.
- rtype
DataFrame
..
- set_params(**params)[source]#
Set the parameters of this estimator.
The method works on simple estimators as well as on nested objects (such as
Pipeline
). The latter have parameters of the form<component>__<parameter>
so that it’s possible to update each component of a nested object.- Parameters
- **paramsdict
Estimator parameters.
- Returns
- selfestimator instance
Estimator instance.