Source code for torch_geometric.nn.dense.dense_sage_conv

import torch
import torch.nn.functional as F
from torch import Tensor
from torch.nn import Linear

from torch_geometric.typing import OptTensor

[docs]class DenseSAGEConv(torch.nn.Module): r"""See :class:`torch_geometric.nn.conv.SAGEConv`. .. note:: :class:`~torch_geometric.nn.dense.DenseSAGEConv` expects to work on binary adjacency matrices. If you want to make use of weighted dense adjacency matrices, please use :class:`torch_geometric.nn.dense.DenseGraphConv` instead. """ def __init__( self, in_channels: int, out_channels: int, normalize: bool = False, bias: bool = True, ): super().__init__() self.in_channels = in_channels self.out_channels = out_channels self.normalize = normalize self.lin_rel = Linear(in_channels, out_channels, bias=False) self.lin_root = Linear(in_channels, out_channels, bias=bias) self.reset_parameters()
[docs] def reset_parameters(self): r"""Resets all learnable parameters of the module.""" self.lin_rel.reset_parameters() self.lin_root.reset_parameters()
[docs] def forward(self, x: Tensor, adj: Tensor, mask: OptTensor = None) -> Tensor: r"""Forward pass. Args: x (torch.Tensor): Node feature tensor :math:`\mathbf{X} \in \mathbb{R}^{B \times N \times F}`, with batch-size :math:`B`, (maximum) number of nodes :math:`N` for each graph, and feature dimension :math:`F`. adj (torch.Tensor): Adjacency tensor :math:`\mathbf{A} \in \mathbb{R}^{B \times N \times N}`. The adjacency tensor is broadcastable in the batch dimension, resulting in a shared adjacency matrix for the complete batch. mask (torch.Tensor, optional): Mask matrix :math:`\mathbf{M} \in {\{ 0, 1 \}}^{B \times N}` indicating the valid nodes for each graph. (default: :obj:`None`) """ x = x.unsqueeze(0) if x.dim() == 2 else x adj = adj.unsqueeze(0) if adj.dim() == 2 else adj B, N, _ = adj.size() out = torch.matmul(adj, x) out = out / adj.sum(dim=-1, keepdim=True).clamp(min=1) out = self.lin_rel(out) + self.lin_root(x) if self.normalize: out = F.normalize(out, p=2.0, dim=-1) if mask is not None: out = out * mask.view(B, N, 1).to(x.dtype) return out
def __repr__(self) -> str: return (f'{self.__class__.__name__}({self.in_channels}, ' f'{self.out_channels})')