You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 

91 lines
3.5 KiB

import awkward as ak
from sklearn.preprocessing import PolynomialFeatures
from sklearn.linear_model import LinearRegression, Lasso
from sklearn.model_selection import train_test_split
from sklearn.metrics import mean_squared_error
import numpy as np
def fit_linear_regression_model(
array: ak.Array,
target_feat: str,
features: list[str],
degree: int,
keep: list[str] = None,
keep_only_linear_in: str = "",
remove: list[str] = None,
include_bias: bool = False,
fit_intercept: bool = False,
test_size=0.2,
random_state=42,
) -> tuple[LinearRegression, list[str], np.array, np.array]:
"""Wrapper around sklearn's LinearRegression with PolynomialFeatures.
Args:
array (ak.Array): The data.
target_feat (str): Target feature to be fitted.
features (list[str]): Features the target depends on.
degree (int): Highest order of the polynomial.
keep (list[str], optional): Monomials to keep. Defaults to None.
keep_only_linear_in (str, optional): Keep only terms that are linear in this feature. Defaults to "".
remove (list[str], optional): Monomials to remove. Defaults to None.
include_bias (bool, optional): Inlcude bias term in polynomial. Defaults to False.
fit_intercept (bool, optional): Fit zeroth order. Defaults to False.
test_size (float, optional): Fraction of data used for testing. Defaults to 0.2.
random_state (int, optional): Defaults to 42.
Raises:
NotImplementedError: Simultaneous removing and keeping is not implemented.
Returns:
tuple[LinearRegression, list[str]]: The linear regression object and the kept features.
"""
data = np.column_stack([ak.to_numpy(array[feat]) for feat in features])
target = ak.to_numpy(array[target_feat])
X_train, X_test, y_train, y_test = train_test_split(
data,
target,
test_size=test_size,
random_state=random_state,
)
poly = PolynomialFeatures(degree=degree, include_bias=include_bias)
X_train_model = poly.fit_transform(X_train)
X_test_model = poly.fit_transform(X_test)
poly_features = poly.get_feature_names_out(input_features=features)
if not remove:
if keep:
remove = [i for i, f in enumerate(poly_features) if f not in keep]
elif keep_only_linear_in:
# remove everything that's not linear in variable
# the corrections should vanish
remove = [
i
for i, f in enumerate(poly_features)
if (keep_only_linear_in not in f) or (keep_only_linear_in + "^" in f)
]
else:
remove = []
elif remove and keep:
raise NotImplementedError
X_train_model = np.delete(X_train_model, remove, axis=1)
X_test_model = np.delete(X_test_model, remove, axis=1)
poly_features = np.delete(poly_features, remove)
lin_reg = LinearRegression(fit_intercept=fit_intercept) # Lasso(alpha=0.01)
lin_reg.fit(X_train_model, y_train)
y_pred_test = lin_reg.predict(X_test_model)
print(f"Parameterisation for {target_feat}:")
print("intercept=", lin_reg.intercept_)
print(
"coef=",
dict(
zip(
poly_features,
lin_reg.coef_,
),
),
)
print("r2 score=", lin_reg.score(X_test_model, y_test))
print("RMSE =", mean_squared_error(y_test, y_pred_test, squared=False))
print()
return (lin_reg, poly_features, y_test, y_pred_test)