[graphgym] Custom aggregation functions

[smorad]

I see that pyg already has a great framework for comparing specific portions of a GNN: https://github.com/snap-stanford/GraphGym#4-user-customization

I don't see a way to compare aggregation functions. Is there a way to compare new aggregation function against sum or mean?

[rusty1s]

You should be able to compare aggregation functions by doing a hyperparameter search over gnn.agg, see here.