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*This model was published in HF papers on 2021-04-20 and contributed to Hugging Face Transformers on 2021-05-20.*


# RoFormer

[RoFormer](https://huggingface.co/papers/2104.09864) introduces Rotary Position Embedding (RoPE) to encode token positions by rotating the inputs in 2D space. This allows a model to track absolute positions and model relative relationships. RoPE can scale to longer sequences, account for the natural decay of token dependencies, and works with the more efficient linear self-attention.

You can find all the RoFormer checkpoints on the [Hub](https://huggingface.co/models?search=roformer).

> [!TIP]
> Click on the RoFormer models in the right sidebar for more examples of how to apply RoFormer to different language tasks.

The example below demonstrates how to predict the `[MASK]` token with [`Pipeline`], [`AutoModel`], and from the command line.

<hfoptions id="usage">
<hfoption id="Pipeline">

```python
# uncomment to install rjieba which is needed for the tokenizer
# !pip install rjieba
from transformers import pipeline


pipe = pipeline(
    task="fill-mask",
    model="junnyu/roformer_chinese_base",
    device=0
)
output = pipe("水在零度时会[MASK]")
print(output)
```

</hfoption>
<hfoption id="AutoModel">

```py
# uncomment to install rjieba which is needed for the tokenizer
# !pip install rjieba
import torch
from transformers import AutoModelForMaskedLM, AutoTokenizer

model = AutoModelForMaskedLM.from_pretrained(
    "junnyu/roformer_chinese_base"
 device_map="auto")
tokenizer = AutoTokenizer.from_pretrained("junnyu/roformer_chinese_base")

input_ids = tokenizer("水在零度时会[MASK]", return_tensors="pt").to(model.device)
outputs = model(**input_ids)
decoded = tokenizer.batch_decode(outputs.logits.argmax(-1), skip_special_tokens=True)
print(decoded)
```

</hfoption>
</hfoptions>

## Notes

- The current RoFormer implementation is an encoder-only model. The original code can be found in the [ZhuiyiTechnology/roformer](https://github.com/ZhuiyiTechnology/roformer) repository.

## RoFormerConfig

[[autodoc]] RoFormerConfig

## RoFormerTokenizer

[[autodoc]] RoFormerTokenizer
    - build_inputs_with_special_tokens
    - get_special_tokens_mask
    - create_token_type_ids_from_sequences
    - save_vocabulary

## RoFormerTokenizerFast

`RoFormerTokenizerFast` is an alias for [`RoFormerTokenizer`].

## RoFormerModel

[[autodoc]] RoFormerModel
    - forward

## RoFormerForCausalLM

[[autodoc]] RoFormerForCausalLM
    - forward

## RoFormerForMaskedLM

[[autodoc]] RoFormerForMaskedLM
    - forward

## RoFormerForSequenceClassification

[[autodoc]] RoFormerForSequenceClassification
    - forward

## RoFormerForMultipleChoice

[[autodoc]] RoFormerForMultipleChoice
    - forward

## RoFormerForTokenClassification

[[autodoc]] RoFormerForTokenClassification
    - forward

## RoFormerForQuestionAnswering

[[autodoc]] RoFormerForQuestionAnswering
    - forward
