|
|
|
|
|
|
|
|
| from typing import List
|
|
|
| import torch
|
|
|
|
|
| def left_pad_and_stack_1d(tensors: List[torch.Tensor]) -> torch.Tensor:
|
| """Left-pad variable-length 1D tensors with NaN and stack them into a batch."""
|
| if not tensors:
|
| raise ValueError("At least one tensor is required.")
|
|
|
| max_len = max(len(c) for c in tensors)
|
| padded = []
|
| for index, c in enumerate(tensors):
|
| if not isinstance(c, torch.Tensor):
|
| raise TypeError(f"Item {index} is not a torch.Tensor.")
|
| if c.ndim != 1:
|
| raise ValueError(f"Item {index} must be 1D; got shape {tuple(c.shape)}.")
|
| padding = torch.full(
|
| size=(max_len - len(c),),
|
| fill_value=torch.nan,
|
| dtype=c.dtype,
|
| device=c.device,
|
| )
|
| padded.append(torch.concat((padding, c), dim=-1))
|
| return torch.stack(padded)
|
|
|
|
|
| left_pad_and_stack_1D = left_pad_and_stack_1d
|
|
|
