README.md

---
license: apache-2.0
datasets:
- projecte-aina/CA-DE_Parallel_Corpus
language:
- de
- ca
metrics:
- bleu
library_name: fairseq
---
## Projecte Aina’s German-Catalan machine translation model
 
## Model description

This model was trained from scratch using the [Fairseq toolkit](https://fairseq.readthedocs.io/en/latest/) on a combination of datasets comprising both Catalan-German data
sourced from Opus, and additional datasets where synthetic Catalan was generated from the Spanish side of Spanish-Germancorpora using 
[Projecte Aina’s Spanish-Catalan model](https://huggingface.co/projecte-aina/aina-translator-es-ca). This gave a total of approximately 100 million sentence pairs.
The model is evaluated on the Flores, NTEU and NTREX evaluation sets.  

## Intended uses and limitations

You can use this model for machine translation from German to Catalan.

## How to use

### Usage
Required libraries:

```bash
pip install ctranslate2 pyonmttok
```

Translate a sentence using python
```python
import ctranslate2
import pyonmttok
from huggingface_hub import snapshot_download
model_dir = snapshot_download(repo_id="projecte-aina/aina-translator-de-ca", revision="main")

tokenizer=pyonmttok.Tokenizer(mode="none", sp_model_path = model_dir + "/spm.model")
tokenized=tokenizer.tokenize("Willkommen beim Projekt Aina")

translator = ctranslate2.Translator(model_dir)
translated = translator.translate_batch([tokenized[0]])
print(tokenizer.detokenize(translated[0][0]['tokens']))
```

## Limitations and bias
At the time of submission, no measures have been taken to estimate the bias and toxicity embedded in the model. 
However, we are well aware that our models may be biased. We intend to conduct research in these areas in the future, and if completed, this model card will be updated. 

## Training

### Training data

The model was trained on a combination of the following datasets:

| Datasets       	|
|-------------------|
| Multi CCAligned |
| WikiMatrix  	|
| GNOME	|
| KDE4    	|
| OpenSubtitles	|
| GlobalVoices|
| Tatoeba |
| Books | 
| Europarl |
| Tilde |
| Multi-Paracawl |
| DGT |
| EU Bookshop |
| NLLB |
| OpenSubtitles |


All corpora except Europarl and Tilde were collected from [Opus](https://opus.nlpl.eu/). 
The Europarl and Tilde corpora are a synthetic parallel corpus created from the original Spanish-Catalan corpora by [SoftCatalà](https://github.com/Softcatala).
Where a Spanish-German corpus was used, synthetic Catalan was generated from the Spanish side using 
[Projecte Aina’s Spanish-Catalan model](https://huggingface.co/projecte-aina/aina-translator-es-ca).


### Training procedure

### Data preparation

 All datasets are deduplicated, filtered for language identification, and filtered to remove any sentence pairs with a cosine similarity of less than 0.75. 
 This is done using sentence embeddings calculated using [LaBSE](https://huggingface.co/sentence-transformers/LaBSE). 
 The filtered datasets are then concatenated to form a final corpus of 6.258.272 and before training the punctuation is normalized using a 
 modified version of the join-single-file.py script from [SoftCatalà](https://github.com/Softcatala/nmt-models/blob/master/data-processing-tools/join-single-file.py)


#### Tokenization

 All data is tokenized using sentencepiece, with a 50 thousand token sentencepiece model  learned from the combination of all filtered training data. 
 This model is included.  

#### Hyperparameters

The model is based on the Transformer-XLarge proposed by [Subramanian et al.](https://aclanthology.org/2021.wmt-1.18.pdf)
The following hyperparameters were set on the Fairseq toolkit:

| Hyperparameter                 	| Value                        	|
|------------------------------------|----------------------------------|
| Architecture                   	| transformer_vaswani_wmt_en_de_big |
| Embedding size                 	| 1024                         	|
| Feedforward size               	| 4096                         	|
| Number of heads                	| 16                           	|
| Encoder layers                 	| 24                           	|
| Decoder layers                 	| 6                            	|
| Normalize before attention     	| True                         	|
| --share-decoder-input-output-embed | True                         	|
| --share-all-embeddings         	| True                         	|
| Effective batch size           	| 48.000                       	|
| Optimizer                      	| adam                         	|
| Adam betas                     	| (0.9, 0.980)                 	|
| Clip norm                      	| 0.0                          	|
| Learning rate                  	| 5e-4                         	|
| Lr. schedurer                  	| inverse sqrt                 	|
| Warmup updates                 	| 8000                         	|
| Dropout                        	| 0.1                          	|
| Label smoothing                	| 0.1                          	|

The model was trained for a total of 29.000 updates. Weights were saved every 1000 updates and reported results are the average of the last 2 checkpoints.

## Evaluation

### Variable and metrics

We use the BLEU score for evaluation on the [Flores-101](https://github.com/facebookresearch/flores), NTEU (unpublished) and [NTREX](https://github.com/MicrosoftTranslator/NTREX) test sets.

### Evaluation results

Below are the evaluation results on the machine translation from German to Catalan compared to [Softcatalà](https://www.softcatala.org/) and 
[Google Translate](https://translate.google.es/?hl=es):

| Test set         	| SoftCatalà | Google Translate | aina-translator-de-ca |
|----------------------|------------|------------------|---------------|
| Flores 101 dev   	| 28,9     	| **35,1**     	| 33,1    	|
| Flores 101 devtest   |29,2   	| **35,9**     	| 33,2     	|
| NTEU | 38,9 | 39,1 | **42,9** |
| NTREX | 25,7 | **31,2** | 29,1 |
| **Average**          	| 30,7   	| **35,3**     	| 34,3      	|

## Additional information

### Author
The Language Technologies Unit from Barcelona Supercomputing Center.

### Contact
For further information, please send an email to <[email protected]>.

### Copyright
Copyright(c) 2023 by Language Technologies Unit, Barcelona Supercomputing Center.

### License
[Apache License, Version 2.0](https://www.apache.org/licenses/LICENSE-2.0)

### Funding
This work has been promoted and financed by the Generalitat de Catalunya through the [Aina project](https://projecteaina.cat/).

### Disclaimer

<details>
<summary>Click to expand</summary>

The model published in this repository is intended for a generalist purpose and is available to third parties under a permissive Apache License, Version 2.0. 

Be aware that the model may have biases and/or any other undesirable distortions.

When third parties deploy or provide systems and/or services to other parties using this model (or any system based on it) 
or become users of the model, they should note that it is their responsibility to mitigate the risks arising from its use and, 
in any event, to comply with applicable regulations, including regulations regarding the use of Artificial Intelligence.

In no event shall the owner and creator of the model (Barcelona Supercomputing Center) 
be liable for any results arising from the use made by third parties.

</details>