fix input format conversion

ece.py

@@ -21,7 +21,6 @@ from torchmetrics.functional.classification.calibration_error import (
     binary_calibration_error,
     multiclass_calibration_error,
 )
-from numpy import ndarray
 
 
 _CITATION = """\
@@ -109,15 +108,21 @@ class ECE(evaluate.Metric):
         predictions = Tensor(predictions)
         references = LongTensor(references)
 
-        max_label = amax(references, list(range(references.dim())))
-        if max_label > 1 and "num_classes" not in kwargs:
-            kwargs["num_classes"] = max_label
+        # Determine number of classes / binary or multiclass
+        binary = True
+        if "num_classes" not in kwargs:
+            max_label = int(amax(references, list(range(references.dim()))))
+            if max_label > 1:
+                kwargs["num_classes"] = max_label
+                binary = False
+        elif kwargs["num_classes"] > 1:
+            binary = False
 
         # Compute the calibration
-        if max_label > 1:
-            ece = multiclass_calibration_error(predictions, references, **kwargs)
-        else:
+        if binary:
             ece = binary_calibration_error(predictions, references, **kwargs)
+        else:
+            ece = multiclass_calibration_error(predictions, references, **kwargs)
         return {
             "ece": float(ece),
         }