Source code for tad_mctc.batch.agnostic

# This file is part of tad-mctc.
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# SPDX-Identifier: Apache-2.0
# Copyright (C) 2024 Grimme Group
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# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
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#     http://www.apache.org/licenses/LICENSE-2.0
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"""
Batch: Agnostic Ops
===================

Batch-agnostic versions of PyTorch operations that do not work with batched and
non-batched tensors out of the box.
"""

from __future__ import annotations

import torch

from ..typing import Tensor

__all__ = ["eye"]




def eye(
    shape: torch.Size | tuple[int, ...],
    value: float = 1.0,
    device: torch.device | None = None,
    dtype: torch.dtype | None = None,
) -> Tensor:
    """
    Create an identity tensor. This version handles a possible batch
    dimension.

    Parameters
    ----------
    tensor : Tensor
        Tensor shape to create the identity tensor from.
    value : float, optional
        Value to fill the diagonal with. Defaults to `1.0`.
    device : :class:`torch.device` | None, optional
        Device to create the tensor on. If `None`, the device of the input
    dtype : :class:`torch.dtype` | None, optional
        Data type of the tensor. If `None`, the data type of the input.

    Returns
    -------
    Tensor
        Possibly batched identity tensor.
    """
    identity = torch.zeros(shape, device=device, dtype=dtype)
    identity.diagonal(dim1=-2, dim2=-1).fill_(value)
    return identity