update init

Author: lucidrains

vector_quantize_pytorch/sim_vq.py

@@ -29,25 +29,6 @@ def inverse(out, inv_pattern = None):
 
     return packed, inverse
 
-def l2norm(t, dim = -1):
-    return F.normalize(t, dim = dim)
-
-def safe_div(num, den, eps = 1e-6):
-    return num / den.clamp(min = eps)
-
-def efficient_rotation_trick_transform(u, q, e):
-    """
-    4.2 in https://arxiv.org/abs/2410.06424
-    """
-    e = rearrange(e, 'b d -> b 1 d')
-    w = l2norm(u + q, dim = 1).detach()
-
-    return (
-        e -
-        2 * (e @ rearrange(w, 'b d -> b d 1') @ rearrange(w, 'b d -> b 1 d')) +
-        2 * (e @ rearrange(u, 'b d -> b d 1').detach() @ rearrange(q, 'b d -> b 1 d').detach())
-    )
-
 # class
 
 class SimVQ(Module):
@@ -61,7 +42,7 @@ def __init__(
         super().__init__()
         self.accept_image_fmap = accept_image_fmap
 
-        codebook = torch.randn(codebook_size, dim)
+        codebook = torch.randn(codebook_size, dim) * (dim ** -0.5)
         codebook = init_fn(codebook)
 
         # the codebook is actually implicit from a linear layer from frozen gaussian or uniform
@@ -89,25 +70,7 @@ def forward(
 
         # commit loss
 
-        commit_loss = (F.pairwise_distance(x, quantized.detach()) ** 2).mean()
-
-        # straight through
-
-        x, inverse = pack_one(x, '* d')
-        quantized, _ = pack_one(quantized, '* d')
-
-        norm_x = x.norm(dim = -1, keepdim = True)
-        norm_quantize = quantized.norm(dim = -1, keepdim = True)
-
-        rot_quantize = efficient_rotation_trick_transform(
-            safe_div(x, norm_x),
-            safe_div(quantized, norm_quantize),
-            x
-        ).squeeze()
-
-        quantized = rot_quantize * safe_div(norm_quantize, norm_x).detach()
-
-        x, quantized = inverse(x), inverse(quantized)
+        commit_loss = (F.pairwise_distance(x, quantized) ** 2).mean()
 
         # quantized = (quantized - x).detach() + x