add to_dict transform

Author: LarsKue

bayesflow/adapters/transforms/__init__.py

@@ -21,6 +21,7 @@
 from .sqrt import Sqrt
 from .standardize import Standardize
 from .to_array import ToArray
+from .to_dict import ToDict
 from .transform import Transform
 
 from ...utils._docs import _add_imports_to_all

bayesflow/adapters/transforms/to_dict.py

@@ -0,0 +1,41 @@
+import numpy as np
+import pandas as pd
+
+from keras.saving import (
+    register_keras_serializable as serializable,
+)
+
+from .transform import Transform
+
+
+@serializable(package="bayesflow.adapters")
+class ToDict(Transform):
+    """Convert non-dict batches (e.g., pandas.DataFrame) to dict batches"""
+
+    @classmethod
+    def from_config(cls, config: dict, custom_objects=None):
+        return cls()
+
+    def get_config(self) -> dict:
+        return {}
+
+    def forward(self, data, **kwargs) -> dict[str, np.ndarray]:
+        data = dict(data)
+
+        for key, value in data.items():
+            if isinstance(data[key], pd.Series):
+                if value.dtype == "object":
+                    value = value.astype("category")
+
+                if value.dtype == "category":
+                    value = pd.get_dummies(value)
+
+                value = np.asarray(value).astype("float32", copy=False)
+
+            data[key] = value
+
+        return data
+
+    def inverse(self, data: dict[str, np.ndarray], **kwargs) -> dict[str, np.ndarray]:
+        # non-invertible transform
+        return data