GCSAN¶
- Reference:
Chengfeng Xu et al. “Graph Contextualized Self-Attention Network for Session-based Recommendation.” in IJCAI 2019.
- class recbole.model.sequential_recommender.gcsan.GCSAN(config, dataset)[source]¶
Bases:
SequentialRecommender
- GCSAN captures rich local dependencies via graph neural network,
and learns long-range dependencies by applying the self-attention mechanism.
Note
In the original paper, the attention mechanism in the self-attention layer is a single head, for the reusability of the project code, we use a unified transformer component. According to the experimental results, we only applied regularization to embedding.
- calculate_loss(interaction)[source]¶
Calculate the training loss for a batch data.
- Parameters:
interaction (Interaction) – Interaction class of the batch.
- Returns:
Training loss, shape: []
- Return type:
torch.Tensor
- forward(item_seq, item_seq_len)[source]¶
Defines the computation performed at every call.
Should be overridden by all subclasses.
Note
Although the recipe for forward pass needs to be defined within this function, one should call the
Module
instance afterwards instead of this since the former takes care of running the registered hooks while the latter silently ignores them.
- full_sort_predict(interaction)[source]¶
full sort prediction function. Given users, calculate the scores between users and all candidate items.
- Parameters:
interaction (Interaction) – Interaction class of the batch.
- Returns:
Predicted scores for given users and all candidate items, shape: [n_batch_users * n_candidate_items]
- Return type:
torch.Tensor
- predict(interaction)[source]¶
Predict the scores between users and items.
- Parameters:
interaction (Interaction) – Interaction class of the batch.
- Returns:
Predicted scores for given users and items, shape: [batch_size]
- Return type:
torch.Tensor
- training: bool¶
- class recbole.model.sequential_recommender.gcsan.GNN(embedding_size, step=1)[source]¶
Bases:
Module
Graph neural networks are well-suited for session-based recommendation, because it can automatically extract features of session graphs with considerations of rich node connections.
- GNNCell(A, hidden)[source]¶
Obtain latent vectors of nodes via gated graph neural network.
- Parameters:
A (torch.FloatTensor) – The connection matrix,shape of [batch_size, max_session_len, 2 * max_session_len]
hidden (torch.FloatTensor) – The item node embedding matrix, shape of [batch_size, max_session_len, embedding_size]
- Returns:
Latent vectors of nodes,shape of [batch_size, max_session_len, embedding_size]
- Return type:
torch.FloatTensor
- forward(A, hidden)[source]¶
Defines the computation performed at every call.
Should be overridden by all subclasses.
Note
Although the recipe for forward pass needs to be defined within this function, one should call the
Module
instance afterwards instead of this since the former takes care of running the registered hooks while the latter silently ignores them.
- training: bool¶