[Update]update setting of 'auto_collation' and fix errors (#783)

* set 'auto_collation' false when using data transform

* fix data transform error of topopt example

Author: lijialin03

examples/topopt/functions.py

@@ -113,6 +113,8 @@ def augmentation(
     """
     inputs = input_dict["input"]
     labels = label_dict["output"]
+    assert len(inputs.shape) == 3
+    assert len(labels.shape) == 3
 
     # random horizontal flip
     if np.random.random() > 0.5:
@@ -125,7 +127,7 @@ def augmentation(
     # random 90* rotation
     if np.random.random() > 0.5:
         new_perm = list(range(len(inputs.shape)))
-        new_perm[1], new_perm[2] = new_perm[2], new_perm[1]
+        new_perm[-2], new_perm[-1] = new_perm[-1], new_perm[-2]
         inputs = np.transpose(inputs, new_perm)
         labels = np.transpose(labels, new_perm)
 

examples/topopt/topoptmodel.py

@@ -39,7 +39,7 @@ class TopOptNN(ppsci.arch.UNetEx):
 
     Examples:
         >>> import ppsci
-        >>> model = ppsci.arch.ppsci.arch.UNetEx("input", "output", 2, 1, 3, (16, 32, 64), 2, lambda: 1, Flase, False)
+        >>> model = ppsci.arch.ppsci.arch.TopOptNN("input", "output", 2, 1, 3, (16, 32, 64), 2, lambda: 1, Flase, False)
     """
 
     def __init__(

ppsci/data/__init__.py

@@ -134,6 +134,7 @@ def build_dataloader(_dataset, cfg):
         if (
             cfg.get("auto_collation", not getattr(_dataset, "batch_index", False))
             is False
+            and "transforms" not in cfg["dataset"]
         ):
             # 1. wrap batch_sampler again into BatchSampler for disabling auto collation,
             # which can speed up the process of batch samples indexing from dataset. See