Update.

diff --git a/main.py b/main.py
index 55615ee..4dca41f 100755 (executable)
--- a/main.py
+++ b/main.py
@@ -364,6 +364,7 @@ def sigma_for_grids(input):
     l = input.size(1) // 4 - 1
     sigma = input.new(input.size())
     r = sigma.view(sigma.size(0), 4, sigma.size(1) // 4)
+    r[:, :, 0] = 0
     r[:, :, 1:] = (
         torch.rand(input.size(0), 4, l, device=input.device).sort(dim=2).indices
     ) + 1