Why we need remove and add self loop in GAT?

❓ Questions & Help

When I read the code in nn.conv.gat_conv.py, I found it firstly remove the loop and then add it. Why this is necessary?

    def forward(self, x, edge_index):
        """"""
        edge_index, _ = remove_self_loops(edge_index)
        edge_index = add_self_loops(edge_index, num_nodes=x.size(0))

[rusty1s]

Thank you. Added to master.

[rusty1s]

We do this in case there are already (a few) self-loops in the graph. Normally, remove_self_loops is a no-op.