Struct rust_bert::electra::ElectraModel

pub struct ElectraModel { /* private fields */ }

Electra Base model

Base architecture for Electra models. It is made of the following blocks:

• embeddings: token, position and segment_id embeddings. Note that in contrast to BERT, the embeddings dimension is not necessarily equal to the hidden layer dimensions
• encoder: BertEncoder (transformer) made of a vector of layers. Each layer is made of a self-attention layer, an intermediate (linear) and output (linear + layer norm) layers
• embeddings_project: (optional) linear layer applied to project the embeddings space to the hidden layer dimension

Implementations

impl ElectraModel

Defines the implementation of the ElectraModel.

pub fn new<'p, P>(p: P, config: &ElectraConfig) -> ElectraModelwhere
    P: Borrow<Path<'p>>,

Build a new ElectraModel

Arguments

• p - Variable store path for the root of the Electra model
• config - ElectraConfig object defining the model architecture

Example

use rust_bert::electra::{ElectraConfig, ElectraModel};
use rust_bert::Config;
use std::path::Path;
use tch::{nn, Device};

let config_path = Path::new("path/to/config.json");
let device = Device::Cpu;
let p = nn::VarStore::new(device);
let config = ElectraConfig::from_file(config_path);
let electra_model: ElectraModel = ElectraModel::new(&p.root() / "electra", &config);

pub fn forward_t(
    &self,
    input_ids: Option<&Tensor>,
    mask: Option<&Tensor>,
    token_type_ids: Option<&Tensor>,
    position_ids: Option<&Tensor>,
    input_embeds: Option<&Tensor>,
    train: bool
) -> Result<ElectraModelOutput, RustBertError>

Forward pass through the model

Arguments

• input_ids - Optional input tensor of shape (batch size, sequence_length). If None, pre-computed embeddings must be provided (see input_embeds)
• mask - Optional mask of shape (batch size, sequence_length). Masked position have value 0, non-masked value 1. If None set to 1
• token_type_ids - Optional segment id of shape (batch size, sequence_length). Convention is value of 0 for the first sentence (incl. SEP) and 1 for the second sentence. If None set to 0.
• position_ids - Optional position ids of shape (batch size, sequence_length). If None, will be incremented from 0.
• input_embeds - Optional pre-computed input embeddings of shape (batch size, sequence_length, hidden_size). If None, input ids must be provided (see input_ids)
• train - boolean flag to turn on/off the dropout layers in the model. Should be set to false for inference.

Returns

• ElectraModelOutput containing:
  • hidden_state - Tensor of shape (batch size, sequence_length, hidden_size)
  • all_hidden_states - Option<Vec<Tensor>> of length num_hidden_layers with shape (batch size, sequence_length, hidden_size)
  • all_attentions - Option<Vec<Tensor>> of length num_hidden_layers with shape (batch size, sequence_length, hidden_size)

Example

let (batch_size, sequence_length) = (64, 128);
let input_tensor = Tensor::rand(&[batch_size, sequence_length], (Int64, device));
let mask = Tensor::zeros(&[batch_size, sequence_length], (Int64, device));
let token_type_ids = Tensor::zeros(&[batch_size, sequence_length], (Int64, device));
let position_ids = Tensor::arange(sequence_length, (Int64, device))
    .expand(&[batch_size, sequence_length], true);

let model_output = no_grad(|| {
    electra_model
        .forward_t(
            Some(&input_tensor),
            Some(&mask),
            Some(&token_type_ids),
            Some(&position_ids),
            None,
            false,
        )
        .unwrap()
});