ai-privacy-toolkit/apt/utils/models/xgboost_model.py
2022-07-28 17:21:24 +03:00

87 lines
3.8 KiB
Python

from typing import Optional, Tuple
from apt.utils.models import Model, ModelOutputType, ScoringMethod, check_correct_model_output, is_one_hot
from apt.utils.datasets import Dataset, OUTPUT_DATA_ARRAY_TYPE
from xgboost import XGBClassifier
import numpy as np
from art.estimators.classification.xgboost import XGBoostClassifier as ArtXGBoostClassifier
class XGBoostModel(Model):
"""
Wrapper class for xgboost models.
"""
class XGBoostClassifier(XGBoostModel):
"""
Wrapper class for xgboost classification models.
:param model: The original xgboost model object. Must be fit.
:type model: Booster or XGBClassifier object
:param output_type: The type of output the model yields (vector/label only)
:type output_type: `ModelOutputType`
:param input_shape: Shape of input to the model.
:type input_shape: Tuple[int, ...]
:param nb_classes: Number of prediction classes of the model.
:type nb_classes: int
:param black_box_access: Boolean describing the type of deployment of the model (when in production).
Set to True if the model is only available via query (API) access, i.e.,
only the outputs of the model are exposed, and False if the model internals
are also available. Default is True.
:type black_box_access: boolean, optional
:param unlimited_queries: If black_box_access is True, this boolean indicates whether a user can perform
unlimited queries to the model API or whether there is a limit to the number of
queries that can be submitted. Default is True.
:type unlimited_queries: boolean, optional
"""
def __init__(self, model: XGBClassifier, output_type: ModelOutputType, input_shape: Tuple[int, ...],
nb_classes: int,black_box_access: Optional[bool] = True,
unlimited_queries: Optional[bool] = True, **kwargs):
super().__init__(model, output_type, black_box_access, unlimited_queries, **kwargs)
self._art_model = ArtXGBoostClassifier(model, nb_features=input_shape[0], nb_classes=nb_classes)
self.nb_classes = nb_classes
def fit(self, train_data: Dataset, **kwargs) -> None:
"""
Fit the model using the training data.
:param train_data: Training data. Labels are expected to either be one-hot encoded or a 1D-array of categorical
labels (consecutive integers starting at 0).
:type train_data: `Dataset`
:return: None
"""
self._art_model._model.fit(train_data.get_samples(), train_data.get_labels())
def predict(self, x: Dataset, **kwargs) -> OUTPUT_DATA_ARRAY_TYPE:
"""
Perform predictions using the model for input `x`.
:param x: Input samples.
:type x: `Dataset`
:return: Predictions from the model as numpy array (class probabilities, if supported).
"""
predictions = self._art_model.predict(x.get_samples(), **kwargs)
check_correct_model_output(predictions, self.output_type)
return predictions
def score(self, test_data: Dataset, scoring_method: Optional[ScoringMethod] = ScoringMethod.ACCURACY, **kwargs):
"""
Score the model using test data.
:param test_data: Test data.
:type train_data: `Dataset`
:return: the score as float (for classifiers, between 0 and 1)
"""
y = test_data.get_labels()
predicted = self.predict(test_data)
if is_one_hot(predicted):
predicted = np.argmax(predicted, axis=1)
if is_one_hot(y):
y = np.argmax(y, axis=1)
if scoring_method == ScoringMethod.ACCURACY:
return np.count_nonzero(y == predicted) / predicted.shape[0]
else:
raise NotImplementedError