Can't call numpy() on Tensor that requires grad. Use tensor.detach().numpy() instead

This error occurs when you try to call the numpy method on a PyTorch tensor that requires gradient computation. To fix this error, you need to detach the tensor from the computation graph before calling the numpy method. You can do this by calling the detach() method on the tensor before calling numpy().

For example:

import torch

# create a tensor
x = torch.tensor([1, 2, 3], requires_grad=True)

# detach the tensor from the computation graph
x_np = x.detach().numpy()

# print the numpy array
print(x_np)

In the code above, we first create a tensor and set the requires_grad flag to True, indicating that we want to compute gradients with respect to this tensor. We then detach the tensor from the computation graph by calling the detach() method on it. Finally, we call the numpy method on the detached tensor to get the corresponding numpy array.