#  Copyright (c) 2021. Lucas G. S. Jeub
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import torch
import torch_geometric as tg
from torch.nn import functional as F
[docs]
class GAEconv(torch.nn.Module):
    """
    implements the convolution operator for use with :class:`tg.nn.GAE`
    """
[docs]
    def __init__(self, dim, num_node_features, hidden_dim=32, cached=True, bias=True, add_self_loops=True, normalize=True):
        """
        Initialise parameters
        Args:
            dim: output dimension
            num_node_features: input dimension
            hidden_dim: hidden dimension
            cached: if ``True``, cache the normalised adjacency matrix after first call
            bias: if ``True``, include bias terms
            add_self_loops: if ``True``, add self loops before normalising
            normalize: if ``True``, normalise adjacency matrix
        """
        super().__init__()
        self.conv1 = tg.nn.GCNConv(num_node_features, hidden_dim, cached=cached, bias=bias, add_self_loops=add_self_loops,
                                   normalize=normalize)
        self.conv2 = tg.nn.GCNConv(hidden_dim, dim, cached=cached, bias=bias, add_self_loops=add_self_loops,
                                   normalize=normalize) 
[docs]
    def forward(self, data):
        """compute coordinates given data"""
        edge_index = data.edge_index
        x = F.relu(self.conv1(data.x, edge_index))
        return self.conv2(x, edge_index)