distilbert-base-nepali

distilbert-base-nepali

This model is pre-trained on nepalitext dataset consisting of over 13 million Nepali text sequences using a masked language modeling (MLM) objective. Our approach trains a Sentence Piece Model (SPM) for text tokenization similar to XLM-ROBERTa and trains distilbert model for language modeling. Find more details in this paper.

It achieves the following results on the evaluation set:

Model description

Refer to original distilbert-base-uncased

Intended uses & limitations

This backbone model intends to be fine-tuned on Nepali language focused downstream task such as sequence classification, token classification or question answering. The language model being trained on a data with texts grouped to a block size of 512, it handles text sequence up to 512 tokens and may not perform satisfactorily on shorter sequences.

Usage

This model can be used directly with a pipeline for masked language modeling:

>>> from transformers import pipeline
>>> unmasker = pipeline('fill-mask', model='Sakonii/distilbert-base-nepali')
>>> unmasker("मानविय गतिविधिले प्रातृतिक पर्यावरन प्रनालीलाई अपरिमेय क्षति पु्र्याएको छ। परिवर्तनशिल जलवायुले खाध, सुरक्षा, <mask>, जमिन, मौसमलगायतलाई असंख्य तरिकाले प्रभावित छ।")

[{'score': 0.04128897562623024,
  'sequence': 'मानविय गतिविधिले प्रातृतिक पर्यावरन प्रनालीलाई अपरिमेय क्षति पु्र्याएको छ। परिवर्तनशिल जलवायुले खाध, सुरक्षा, मौसम, जमिन, मौसमलगायतलाई असंख्य तरिकाले प्रभावित छ।',
  'token': 2605,
  'token_str': 'मौसम'},
 {'score': 0.04100276157259941,
  'sequence': 'मानविय गतिविधिले प्रातृतिक पर्यावरन प्रनालीलाई अपरिमेय क्षति पु्र्याएको छ। परिवर्तनशिल जलवायुले खाध, सुरक्षा, प्रकृति, जमिन, मौसमलगायतलाई असंख्य तरिकाले प्रभावित छ।',
  'token': 2792,
  'token_str': 'प्रकृति'},
 {'score': 0.026525357738137245,
  'sequence': 'मानविय गतिविधिले प्रातृतिक पर्यावरन प्रनालीलाई अपरिमेय क्षति पु्र्याएको छ। परिवर्तनशिल जलवायुले खाध, सुरक्षा, पानी, जमिन, मौसमलगायतलाई असंख्य तरिकाले प्रभावित छ।',
  'token': 387,
  'token_str': 'पानी'},
 {'score': 0.02340106852352619,
  'sequence': 'मानविय गतिविधिले प्रातृतिक पर्यावरन प्रनालीलाई अपरिमेय क्षति पु्र्याएको छ। परिवर्तनशिल जलवायुले खाध, सुरक्षा, जल, जमिन, मौसमलगायतलाई असंख्य तरिकाले प्रभावित छ।',
  'token': 1313,
  'token_str': 'जल'},
 {'score': 0.02055591531097889,
  'sequence': 'मानविय गतिविधिले प्रातृतिक पर्यावरन प्रनालीलाई अपरिमेय क्षति पु्र्याएको छ। परिवर्तनशिल जलवायुले खाध, सुरक्षा, वातावरण, जमिन, मौसमलगायतलाई असंख्य तरिकाले प्रभावित छ।',
  'token': 790,
  'token_str': 'वातावरण'}]

Here is how we can use the model to get the features of a given text in PyTorch:

from transformers import AutoTokenizer, AutoModelForMaskedLM

tokenizer = AutoTokenizer.from_pretrained('Sakonii/distilbert-base-nepali')
model = AutoModelForMaskedLM.from_pretrained('Sakonii/distilbert-base-nepali')

# prepare input
text = "चाहिएको text यता राख्नु होला।"
encoded_input = tokenizer(text, return_tensors='pt')

# forward pass
output = model(**encoded_input)

Training data

This model is trained on nepalitext language modeling dataset which combines the datasets: OSCAR , cc100 and a set of scraped Nepali articles on Wikipedia. As for training the language model, the texts in the training set are grouped to a block of 512 tokens.

Tokenization

A Sentence Piece Model (SPM) is trained on a subset of nepalitext dataset for text tokenization. The tokenizer trained with vocab-size=24576, min-frequency=4, limit-alphabet=1000 and model-max-length=512.

Training procedure

The model is trained with the same configuration as the original distilbert-base-uncased; 512 tokens per instance, 28 instances per batch, and around 35.7K training steps.

Training hyperparameters

The following hyperparameters were used for training of the final epoch: [ Refer to the Training results table below for varying hyperparameters every epoch ]

• learning_rate: 5e-05
• train_batch_size: 28
• eval_batch_size: 8
• seed: 42
• optimizer: Adam with betas=(0.9,0.999) and epsilon=1e-08
• lr_scheduler_type: linear
• num_epochs: 1
• mixed_precision_training: Native AMP

Training results

The model is trained for 4 epochs with varying hyperparameters:

Final model evaluated with MLM Probability of 15%:

Framework versions

• Transformers 4.16.2
• Pytorch 1.9.1
• Datasets 1.18.3
• Tokenizers 0.10.3