'numpy.ndarray' object has no attribute 'detach'

This error typically occurs when you try to call the `detach()` method on a NumPy array, which is not supported.

The `detach()` method is a PyTorch method that is used to detach a tensor from its computation graph. NumPy arrays do not have computation graphs as they are not part of any deep learning framework.

To fix this error, you need to make sure that you are calling `detach()` on a PyTorch tensor rather than a NumPy array. If you need to convert a NumPy array to a PyTorch tensor, you can use the `torch.from_numpy()` method.

Example:

import numpy as np
import torch

# create a NumPy array
arr = np.array([1, 2, 3])

# convert the NumPy array to a PyTorch tensor
tensor = torch.from_numpy(arr)

# detach the tensor from its computation graph
detached_tensor = tensor.detach()