README.md

---
license: mit
language:
- ru
- en
tags:
- transformers
- sentence-transformers
---

# Model Card for ru-en-RoSBERTa

The ru-en-RoSBERTa is a general text embedding model for Russian. The model is based on [ruRoBERTa](https://huggingface.co/ai-forever/ruRoberta-large) and fine-tuned with ~4M pairs of supervised, synthetic and unsupervised data in Russian and English. Tokenizer supports some English tokens from [RoBERTa](https://huggingface.co/FacebookAI/roberta-large) tokenizer.

For more model details please refer to our [article](arxiv).

## Usage

The model can be used as is with prefixes. It is recommended to use CLS pooling. The choice of prefix and pooling depends on the task. 

We use the following basic rules to choose a prefix:
- `"search_query: "` and `"search_document: "` prefixes are for answer or relevant paragraph retrieval
- `"classification: "` prefix is for symmetric paraphrasing related tasks (STS, NLI, Bitext Mining)
- `"clustering: "` prefix is for any tasks that rely on thematic features (topic classification, title-body retrieval)

To better tailor the model to your needs, you can fine-tune it with relevant high-quality Russian and English datasets.

Below are examples of texts encoding using the Transformers and SentenceTransformers libraries.

### Transformers

```python
import torch
import torch.nn.functional as F
from transformers import AutoTokenizer, AutoModel


def pool(hidden_state, mask, pooling_method="cls"):
    if pooling_method == "mean":
        s = torch.sum(hidden_state * mask.unsqueeze(-1).float(), dim=1)
        d = mask.sum(axis=1, keepdim=True).float()
        return s / d
    elif pooling_method == "cls":
        return hidden_state[:, 0]

inputs = [
    # 
    "classification: Он нам и <unk> не нужон ваш Интернет!",
    "clustering: В Ярославской области разрешили работу бань, но без посетителей",
    "search_query: Сколько программистов нужно, чтобы вкрутить лампочку?",

    # 
    "classification: What a time to be alive!",
    "clustering: Ярославским баням разрешили работать без посетителей",
    "search_document: Чтобы вкрутить лампочку, требуется три программиста: один напишет программу извлечения лампочки, другой — вкручивания лампочки, а третий проведет тестирование.",
]

tokenizer = AutoTokenizer.from_pretrained("ai-forever/ru-en-RoSBERTa")
model = AutoModel.from_pretrained("ai-forever/ru-en-RoSBERTa")

tokenized_inputs = tokenizer(inputs, max_length=512, padding=True, truncation=True, return_tensors="pt")

with torch.no_grad():
    outputs = model(**tokenized_inputs)
    
embeddings = pool(
    outputs.last_hidden_state, 
    tokenized_inputs["attention_mask"],
    pooling_method="cls" # or try "mean"
)

embeddings = F.normalize(embeddings, p=2, dim=1)

sim_scores = embeddings[:3] @ embeddings[3:].T
print(sim_scores.diag().tolist())
# [0.4796873927116394, 0.9409002065658569, 0.7761015892028809]
```

### SentenceTransformers

```python
from sentence_transformers import SentenceTransformer


inputs = [
    # 
    "classification: Он нам и <unk> не нужон ваш Интернет!",
    "clustering: В Ярославской области разрешили работу бань, но без посетителей",
    "search_query: Сколько программистов нужно, чтобы вкрутить лампочку?",

    # 
    "classification: What a time to be alive!",
    "clustering: Ярославским баням разрешили работать без посетителей",
    "search_document: Чтобы вкрутить лампочку, требуется три программиста: один напишет программу извлечения лампочки, другой — вкручивания лампочки, а третий проведет тестирование.",
]

# loads model with CLS pooling
model = SentenceTransformer("ai-forever/ru-en-RoSBERTa")

# embeddings are normalized by default
embeddings = model.encode(inputs, convert_to_tensor=True)

sim_scores = embeddings[:3] @ embeddings[3:].T
print(sim_scores.diag().tolist())
# [0.47968706488609314, 0.940900444984436, 0.7761018872261047]
```

## Citation

TODO

## Limitations

The model is designed to process texts in Russian, the quality in English is unknown. Maximum input text length is limited to 512 tokens.