"""
This module provides a Decision Tree model wrapper, inheriting
from `aiqclib.common.base.scikit_learn_model_base.SklearnModelBase`.
It facilitates training, prediction, and evaluation of a Decision Tree classifier using
Polars DataFrames, converting them to Pandas for compatibility with the
`sklearn` library.
"""
from typing import Dict, Any
from sklearn.tree import DecisionTreeClassifier as SklearnDT
from aiqclib.common.base.config_base import ConfigBase
from aiqclib.common.base.scikit_learn_model_base import SklearnModelBase
[docs]
class DecisionTree(SklearnModelBase):
"""
A Decision Tree model wrapper class for training and testing.
Inherits from :class:`SklearnModelBase` to reuse common Scikit-Learn API logic.
Features include:
- Automatic application of ``model_params`` from the YAML config, if defined;
otherwise, uses default hyperparameters.
- Uses ``sklearn.tree.DecisionTreeClassifier``.
.. note::
This class sets :attr:`expected_class_name` to ``"DecisionTree"``.
Single Decision Trees in scikit-learn generally do not support the ``n_jobs`` parameter.
"""
expected_class_name: str = "DecisionTree"
short_name: str = "DT"
def __init__(self, config: ConfigBase) -> None:
"""
Initialize the Decision Tree model with default or user-specified parameters.
:param config: A configuration object providing model parameters.
:type config: aiqclib.common.base.config_base.ConfigBase
"""
super().__init__(config=config)
self.model_params: Dict[str, Any] = {
"criterion": "gini",
"splitter": "best",
"max_depth": 10,
"min_samples_split": 10,
"min_samples_leaf": 5,
"max_features": None,
"random_state": None,
"class_weight": "balanced",
"ccp_alpha": 0.001,
}
# Update model parameters with config step parameters
model_params = self.config.get_model_params(
self.expected_class_name, self.short_name
)
self.model_params.update(model_params)
def _get_model_class(self) -> Any:
"""
Return the Scikit-Learn DecisionTreeClassifier class.
:return: The DecisionTreeClassifier class.
:rtype: typing.Any
"""
return SklearnDT