How to correctly set num_nodes for a PairData object?

[kyriakosschwarz]

For a PairData object I get this warning:

UserWarning: Unable to accurately infer 'num_nodes' from the attribute set '{'edge_attr_a', 'x_b', 'x_a', 'id', 'edge_index_a', 'edge_index_b', 'expression', 'edge_attr_b', 'y'}'. Please explicitly set 'num_nodes' as an attribute of 'data' to suppress this warning

For batching purposes, how do I correctly set the 'num_nodes' attribute? Just the sum of nodes of both graphs, or something else?

Thanks a lot for any help!

[rusty1s]

Thanks for reporting. PyG raises this warning as it fails to compute the batch vector, which you do not need in your case anyways. As such, you can ignore the warning as it will not do any harm in your case.

Nonetheless, I fixed this issue in master, see #3298. This should avoid printing the warning for PairData in the first place.

[kyriakosschwarz]

Great, thanks a lot!