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| 1 | +"""LogregAimedEmbedding class for a proxy optimzation of embedding.""" |
| 2 | + |
| 3 | +from typing import Literal |
| 4 | + |
| 5 | +import numpy as np |
| 6 | +from numpy.typing import NDArray |
| 7 | +from sklearn.linear_model import LogisticRegression, LogisticRegressionCV |
| 8 | +from sklearn.multioutput import MultiOutputClassifier |
| 9 | +from sklearn.preprocessing import LabelEncoder |
| 10 | + |
| 11 | +from autointent import Context, Embedder |
| 12 | +from autointent.context.optimization_info import RetrieverArtifact |
| 13 | +from autointent.custom_types import ListOfLabels |
| 14 | +from autointent.metrics import SCORING_METRICS_MULTICLASS, SCORING_METRICS_MULTILABEL |
| 15 | +from autointent.modules.abc import EmbeddingModule |
| 16 | + |
| 17 | + |
| 18 | +class LogregAimedEmbedding(EmbeddingModule): |
| 19 | + r""" |
| 20 | + Module for configuring embeddings optimized for linear classification. |
| 21 | +
|
| 22 | + The main purpose of this module is to be used at embedding node for optimizing |
| 23 | + embedding configuration using its logreg classification quality as a sort of proxy metric. |
| 24 | +
|
| 25 | + :ivar classifier: The trained logistic regression model. |
| 26 | + :ivar label_encoder: Label encoder for converting labels to numerical format. |
| 27 | + :ivar name: Name of the module, defaults to "logreg". |
| 28 | +
|
| 29 | + Examples |
| 30 | + -------- |
| 31 | + .. testcode:: |
| 32 | +
|
| 33 | + from autointent.modules.embedding import LogregAimedEmbedding |
| 34 | + utterances = ["bye", "how are you?", "good morning"] |
| 35 | + labels = [0, 1, 1] |
| 36 | + retrieval = LogregAimedEmbedding( |
| 37 | + embedder_name="sergeyzh/rubert-tiny-turbo", |
| 38 | + cv=2 |
| 39 | + ) |
| 40 | + retrieval.fit(utterances, labels) |
| 41 | + """ |
| 42 | + |
| 43 | + _classifier: LogisticRegressionCV | MultiOutputClassifier |
| 44 | + _label_encoder: LabelEncoder | None |
| 45 | + name = "logreg" |
| 46 | + supports_multiclass = True |
| 47 | + supports_multilabel = True |
| 48 | + supports_oos = False |
| 49 | + |
| 50 | + def __init__( |
| 51 | + self, |
| 52 | + embedder_name: str, |
| 53 | + cv: int = 3, |
| 54 | + embedder_device: str = "cpu", |
| 55 | + embedder_batch_size: int = 32, |
| 56 | + embedder_max_length: int | None = None, |
| 57 | + embedder_use_cache: bool = True, |
| 58 | + ) -> None: |
| 59 | + """ |
| 60 | + Initialize the LogregAimedEmbedding. |
| 61 | +
|
| 62 | + :param cv: the number of folds used in LogisticRegressionCV |
| 63 | + :param embedder_name: Name of the embedder used for creating embeddings. |
| 64 | + :param embedder_device: Device to run operations on, e.g., "cpu" or "cuda". |
| 65 | + :param batch_size: Batch size for embedding generation. |
| 66 | + :param max_length: Maximum sequence length for embeddings. None if not set. |
| 67 | + :param embedder_use_cache: Flag indicating whether to cache intermediate embeddings. |
| 68 | + """ |
| 69 | + self.embedder_name = embedder_name |
| 70 | + self.embedder_device = embedder_device |
| 71 | + self.embedder_batch_size = embedder_batch_size |
| 72 | + self.embedder_max_length = embedder_max_length |
| 73 | + self.embedder_use_cache = embedder_use_cache |
| 74 | + self.cv = cv |
| 75 | + |
| 76 | + @classmethod |
| 77 | + def from_context( |
| 78 | + cls, |
| 79 | + context: Context, |
| 80 | + cv: int, |
| 81 | + embedder_name: str, |
| 82 | + ) -> "LogregAimedEmbedding": |
| 83 | + """ |
| 84 | + Create a LogregAimedEmbedding instance using a Context object. |
| 85 | +
|
| 86 | + :param cv: the number of folds used in LogisticRegressionCV |
| 87 | + :param context: The context containing configurations and utilities. |
| 88 | + :param embedder_name: Name of the embedder to use. |
| 89 | + :return: Initialized LogregAimedEmbedding instance. |
| 90 | + """ |
| 91 | + return cls( |
| 92 | + cv=cv, |
| 93 | + embedder_name=embedder_name, |
| 94 | + embedder_device=context.get_device(), |
| 95 | + embedder_batch_size=context.get_batch_size(), |
| 96 | + embedder_max_length=context.get_max_length(), |
| 97 | + embedder_use_cache=context.get_use_cache(), |
| 98 | + ) |
| 99 | + |
| 100 | + def clear_cache(self) -> None: |
| 101 | + pass |
| 102 | + |
| 103 | + def fit(self, utterances: list[str], labels: ListOfLabels) -> None: |
| 104 | + """ |
| 105 | + Train the logistic regression model using the provided utterances and labels. |
| 106 | +
|
| 107 | + :param utterances: List of text data to index. |
| 108 | + :param labels: List of corresponding labels for the utterances. |
| 109 | + """ |
| 110 | + self._validate_task(labels) |
| 111 | + |
| 112 | + self._embedder = Embedder( |
| 113 | + device=self.embedder_device, |
| 114 | + model_name_or_path=self.embedder_name, |
| 115 | + batch_size=self.embedder_batch_size, |
| 116 | + max_length=self.embedder_max_length, |
| 117 | + use_cache=self.embedder_use_cache, |
| 118 | + ) |
| 119 | + embeddings = self._embedder.embed(utterances) |
| 120 | + |
| 121 | + if self._multilabel: |
| 122 | + self._label_encoder = None |
| 123 | + base_clf = LogisticRegression() |
| 124 | + self._classifier = MultiOutputClassifier(base_clf) |
| 125 | + else: |
| 126 | + self._label_encoder = LabelEncoder() |
| 127 | + labels = self._label_encoder.fit_transform(labels) |
| 128 | + self._classifier = LogisticRegressionCV(cv=self.cv) |
| 129 | + |
| 130 | + self._classifier.fit(embeddings, labels) |
| 131 | + |
| 132 | + def score( |
| 133 | + self, |
| 134 | + context: Context, |
| 135 | + split: Literal["validation", "test"], |
| 136 | + ) -> dict[str, float | str]: |
| 137 | + """ |
| 138 | + Evaluate the embedding model using a specified metric function. |
| 139 | +
|
| 140 | + :param context: The context containing test data and labels. |
| 141 | + :param split: Target split |
| 142 | + :return: Computed metrics value for the test set or error code of metrics |
| 143 | + """ |
| 144 | + if split == "validation": |
| 145 | + utterances = context.data_handler.validation_utterances(0) |
| 146 | + labels = context.data_handler.validation_labels(0) |
| 147 | + elif split == "test": |
| 148 | + utterances = context.data_handler.test_utterances() |
| 149 | + labels = context.data_handler.test_labels() |
| 150 | + else: |
| 151 | + message = f"Invalid split '{split}' provided. Expected one of 'validation', or 'test'." |
| 152 | + raise ValueError(message) |
| 153 | + |
| 154 | + probas = self.predict(utterances) |
| 155 | + metrics_dict = SCORING_METRICS_MULTILABEL if context.is_multilabel() else SCORING_METRICS_MULTICLASS |
| 156 | + return self.score_metrics((labels, probas), metrics_dict) |
| 157 | + |
| 158 | + def get_assets(self) -> RetrieverArtifact: |
| 159 | + """ |
| 160 | + Get the classifier artifacts for this module. |
| 161 | +
|
| 162 | + :return: A RetrieverArtifact object containing embedder information. |
| 163 | + """ |
| 164 | + return RetrieverArtifact(embedder_name=self.embedder_name) |
| 165 | + |
| 166 | + def predict(self, utterances: list[str]) -> NDArray[np.float64]: |
| 167 | + embeddings = self._embedder.embed(utterances) |
| 168 | + probas = self._classifier.predict_proba(embeddings) |
| 169 | + |
| 170 | + if self._multilabel: |
| 171 | + probas = np.stack(probas, axis=1)[..., 1] |
| 172 | + |
| 173 | + return probas # type: ignore[no-any-return] |
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