Correctly track train / validation losses

bayesflow/approximators/backend_approximators/tensorflow_approximator.py

@@ -12,7 +12,10 @@
 
     def test_step(self, data: dict[str, any]) -> dict[str, tf.Tensor]:
         kwargs = filter_kwargs(data | {"stage": "validation"}, self.compute_metrics)
-        return self.compute_metrics(**kwargs)
+        metrics = self.compute_metrics(**kwargs)
+        loss = metrics["loss"]
+        self._loss_tracker.update_state(loss)
+        return metrics
 
     def train_step(self, data: dict[str, any]) -> dict[str, tf.Tensor]:
         with tf.GradientTape() as tape:

bayesflow/approximators/backend_approximators/torch_approximator.py

@@ -12,7 +12,10 @@
 
     def test_step(self, data: dict[str, any]) -> dict[str, torch.Tensor]:
         kwargs = filter_kwargs(data | {"stage": "validation"}, self.compute_metrics)
-        return self.compute_metrics(**kwargs)
+        metrics = self.compute_metrics(**kwargs)
+        loss = metrics["loss"]
+        self._loss_tracker.update_state(loss)
+        return metrics
 
     def train_step(self, data: dict[str, any]) -> dict[str, torch.Tensor]:
         with torch.enable_grad():

bayesflow/approximators/continuous_approximator.py

@@ -150,14 +150,9 @@ def compute_metrics(
             inference_variables, conditions=inference_conditions, sample_weight=sample_weight, stage=stage
         )
 
-        loss = inference_metrics.get("loss", keras.ops.zeros(())) + summary_metrics.get("loss", keras.ops.zeros(()))
+        loss = inference_metrics["loss"] + summary_metrics.get("loss", keras.ops.zeros(()))
 
-        inference_metrics = {f"{key}/inference_{key}": value for key, value in inference_metrics.items()}
-        summary_metrics = {f"{key}/summary_{key}": value for key, value in summary_metrics.items()}
-
-        metrics = {"loss": loss} | inference_metrics | summary_metrics
-
-        return metrics
+        return {"loss": loss}
 
     def fit(self, *args, **kwargs):
         """