Fix: pulsating sphere transformation (#69)

* add pulsating sphere datasets

* add dataset

* change test use small dataset

* rm mv to cuda

* fix transformation

src/nos/data/pulsating_sphere.py

@@ -63,7 +63,7 @@ def __getitem__(self, idx: int) -> tuple[torch.Tensor, torch.Tensor, torch.Tenso
         x_min = torch.tensor([[0.0], [-1.0], [0.0], [-1.0], [400.0]])
         x_scale = torch.tensor([[1.0], [1.0], [1.0], [1.0], [100.0]])
         x = ((self.x[idx] - x_min) / x_scale) * 2.0 - 1.0
-        v_max, _ = torch.max(torch.abs(self.v[idx]), dim=-1, keepdim=True)
+        v_max, _ = torch.max(torch.abs(self.v[idx]), dim=1, keepdim=True)
 
         return x, x, self.y[idx] * 2.0 - 1.0, self.v[idx] / v_max
 
@@ -142,7 +142,7 @@ def __init__(
     def __getitem__(self, idx: int) -> tuple[torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor]:
         """Get item at idx from dataset."""
         x = self.x[idx] * 2.0 - 1.0
-        u_max, _ = torch.max(torch.abs(self.u[idx]), dim=-1, keepdim=True)
+        u_max, _ = torch.max(torch.abs(self.u[idx]), dim=1, keepdim=True)
         u = self.u[idx] / u_max
 
         y = self.y[idx] * 2.0 - 1.0