Add BERTopic.

LLMTopicDetection_BERTopic/bertopic/dimensionality/_base.py

@@ -0,0 +1,26 @@
+import numpy as np
+
+
+class BaseDimensionalityReduction:
+    """The Base Dimensionality Reduction class.
+
+    You can use this to skip over the dimensionality reduction step in BERTopic.
+
+    Examples:
+    This will skip over the reduction step in BERTopic:
+
+    ```python
+    from bertopic import BERTopic
+    from bertopic.dimensionality import BaseDimensionalityReduction
+
+    empty_reduction_model = BaseDimensionalityReduction()
+
+    topic_model = BERTopic(umap_model=empty_reduction_model)
+    ```
+    """
+
+    def fit(self, X: np.ndarray = None):
+        return self
+
+    def transform(self, X: np.ndarray) -> np.ndarray:
+        return X