address https://github.com/lucidrains/vit-pytorch/issues/351

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "vit-pytorch"
-version = "1.15.7"
+version = "1.16.0"
 description = "Vision Transformer (ViT) - Pytorch"
 readme = { file = "README.md", content-type = "text/markdown" }
 license = { file = "LICENSE" }

vit_pytorch/vaat.py

@@ -735,7 +735,7 @@ if __name__ == '__main__':
         mlp_dim = 384 * 4
     )
 
-    vat = VAAT(
+    vaat = VAAT(
         vit,
         ast,
         dim = 512,
@@ -767,11 +767,11 @@ if __name__ == '__main__':
 
     actions = torch.randn(2, 7, 20)         # actions for learning
 
-    loss = vat(images, audio, actions = actions, tasks = tasks, extra = extra, freeze_vit = True)
+    loss = vaat(images, audio, actions = actions, tasks = tasks, extra = extra, freeze_vit = True)
     loss.backward()
 
     # after much training
 
-    pred_actions, hiddens = vat(images, audio, tasks = tasks, extra = extra, return_hiddens = True)
+    pred_actions, hiddens = vaat(images, audio, tasks = tasks, extra = extra, return_hiddens = True)
 
     assert pred_actions.shape == (2, 7, 20)

vit_pytorch/vit.py

@@ -90,7 +90,9 @@ class ViT(nn.Module):
 
         num_patches = (image_height // patch_height) * (image_width // patch_width)
         patch_dim = channels * patch_height * patch_width
+
         assert pool in {'cls', 'mean'}, 'pool type must be either cls (cls token) or mean (mean pooling)'
+        num_cls_tokens = 1 if pool == 'cls' else 0
 
         self.to_patch_embedding = nn.Sequential(
             Rearrange('b c (h p1) (w p2) -> b (h w) (p1 p2 c)', p1 = patch_height, p2 = patch_width),
@@ -99,8 +101,9 @@ class ViT(nn.Module):
             nn.LayerNorm(dim),
         )
 
-        self.pos_embedding = nn.Parameter(torch.randn(1, num_patches + 1, dim))
-        self.cls_token = nn.Parameter(torch.randn(1, 1, dim))
+        self.cls_token = nn.Parameter(torch.randn(1, num_cls_tokens, dim))
+        self.pos_embedding = nn.Parameter(torch.randn(1, num_patches + num_cls_tokens, dim))
+
         self.dropout = nn.Dropout(emb_dropout)
 
         self.transformer = Transformer(dim, depth, heads, dim_head, mlp_dim, dropout)
@@ -114,7 +117,7 @@ class ViT(nn.Module):
         x = self.to_patch_embedding(img)
         b, n, _ = x.shape
 
-        cls_tokens = repeat(self.cls_token, '1 1 d -> b 1 d', b = b)
+        cls_tokens = repeat(self.cls_token, '1 ... d -> b ... d', b = b)
         x = torch.cat((cls_tokens, x), dim=1)
         x += self.pos_embedding[:, :(n + 1)]
         x = self.dropout(x)