gators.scalers.StandardScaler

class gators.scalers.StandardScaler(inplace: bool = True)[source]

Scale each column by setting the mean to 0 and the standard deviation to 1.

Parameters
inplacebool, default True.

If True, perform the scaling in-place. If False, create new columns.

Examples

Imports and initialization:

>>> from gators.scalers import StandardScaler
>>> obj = StandardScaler()

The fit, transform, and fit_transform methods accept:

  • dask dataframes:

>>> import dask.dataframe as dd
>>> import pandas as pd
>>> X = dd.from_pandas(pd.DataFrame({'A': [1, 2, 3], 'B': [-0.1, 0.2, 0.3]}), npartitions=1)
  • koalas dataframes:

>>> import databricks.koalas as ks
>>> X = ks.DataFrame({'A': [1, 2, 3], 'B': [-0.1, 0.2, 0.3]})
  • and pandas dataframes:

>>> import pandas as pd
>>> X = pd.DataFrame({'A': [1, 2, 3], 'B': [-0.1, 0.2, 0.3]})

The result is a transformed dataframe belonging to the same dataframe library.

>>> obj.fit_transform(X)
     A         B
0 -1.0 -1.120897
1  0.0  0.320256
2  1.0  0.800641
>>> X = pd.DataFrame({'A': [1, 2, 3], 'B': [-0.1, 0.2, 0.3]})
>>> _ = obj.fit(X)
>>> obj.transform_numpy(X.to_numpy())
array([[-1.        , -1.12089708],
       [ 0.        ,  0.32025631],
       [ 1.        ,  0.80064077]])
fit(X: Union[pd.DataFrame, ks.DataFrame, dd.DataFrame], y: Union[pd.Series, ks.Series, dd.Series] = None) → gators.scalers.standard_scaler.StandardScaler[source]

Fit the transformer on the pandas/koalas dataframe X.

Parameters
XDataFrame.

Input dataframe.

ySeries, default None.

Target values.

Returns
self‘StandardScaler’

Instance of itself.

static check_array(X: numpy.ndarray)

Validate array.

Parameters
Xnp.ndarray

Array.

check_array_is_numerics(X: numpy.ndarray)

Check if array is only numerics.

Parameters
Xnp.ndarray

Array.

static check_binary_target(X: Union[pd.DataFrame, ks.DataFrame, dd.DataFrame], y: Union[pd.Series, ks.Series, dd.Series])

Raise an error if the target is not binary.

Parameters
ySeries

Target values.

static check_dataframe(X: Union[pd.DataFrame, ks.DataFrame, dd.DataFrame])

Validate dataframe.

Parameters
XDataFrame

Dataframe.

static check_dataframe_contains_numerics(X: Union[pd.DataFrame, ks.DataFrame, dd.DataFrame])

Check if dataframe is only numerics.

Parameters
XDataFrame

Dataframe.

static check_dataframe_is_numerics(X: Union[pd.DataFrame, ks.DataFrame, dd.DataFrame])

Check if dataframe is only numerics.

Parameters
XDataFrame

Dataframe.

check_dataframe_with_objects(X: Union[pd.DataFrame, ks.DataFrame, dd.DataFrame])

Check if dataframe contains object columns.

Parameters
XDataFrame

Dataframe.

check_datatype(dtype, accepted_dtypes)

Check if dataframe is only numerics.

Parameters
XDataFrame

Dataframe.

static check_multiclass_target(y: Union[pd.Series, ks.Series, dd.Series])

Raise an error if the target is not discrete.

Parameters
ySeries

Target values.

check_nans(X: Union[pd.DataFrame, ks.DataFrame, dd.DataFrame], columns: List[str])

Raise an error if X contains NaN values.

Parameters
XDataFrame

Dataframe.

theta_vecList[float]

List of columns.

static check_regression_target(y: Union[pd.Series, ks.Series, dd.Series])

Raise an error if the target is not discrete.

Parameters
ySeries

Target values.

static check_target(X: Union[pd.DataFrame, ks.DataFrame, dd.DataFrame], y: Union[pd.Series, ks.Series, dd.Series])

Validate target.

Parameters
XDataFrame

Dataframe.

ySeries

Target values.

fit_transform(X: Union[pd.DataFrame, ks.DataFrame, dd.DataFrame], y: Union[pd.Series, ks.Series, dd.Series] = None) → Union[pd.DataFrame, ks.DataFrame, dd.DataFrame]

Fit and Transform the dataframe X.

Parameters
XDataFrame.

Input dataframe.

ySeries, default None.

Input target.

Returns
XDataFrame

Transformed dataframe.

static get_column_names(inplace: bool, columns: List[str], suffix: str)

Return the names of the modified columns.

Parameters
inplacebool

If True return columns. If False return columns__suffix.

columnsList[str]

List of columns.

suffixstr

Suffix used if inplace is False.

Returns
List[str]

List of column names.

get_params(deep=True)

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.

set_params(**params)

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.

transform(X)

Transform the dataframe X.

Parameters
XDataFrame.

Input dataframe.

Returns
XDataFrame

Transformed dataframe.

transform_numpy(X: numpy.ndarray) → numpy.ndarray

Transform the array X.

Parameters
Xnp.ndarray:

Input array.

Returns
Xnp.ndarray

Transformed array.