Question about Sampling Multiple Edge Types Simultaneously in Heterogeneous Graphs using PyG

[ccoverflow]

Hi, I have a heterogeneous graph data that has been converted to the HeteroData class. This heterogeneous graph data has more than 25 types of edges, each with a timestamp. I need to sample multiple types of edges simultaneously when loading (for example, for a type 1 edge, select other edges within its designated hops (like 2 hops), which have a common parent node and whose occurrence time satisfies the chronological order, to be the neighbors of edge 1, and set to sample n neighbors of edge 1). However, the 'edge_label_index' parameter in 'torch_geometric.loader.link_neighbor_loader' can only accept one type of edge. I have also tried implemented loaders such as HGTLoader, but none of them can achieve the effect I want. I'm wondering if there are similar class methods in PyG that can achieve this goal?

[wsad1]

Currently LinkNeighborLoader can only start sampling from on edge type. And it doesn't support edges other than the seed edge having a timestamp.
But there is an open PR to implement sampling from multiple node types #5521, cc: @Padarn.
And support for edge time in loaders is being worked on.

[ccoverflow]

Thank you for your answer. Do you mean that after homogeneous graph conversion, edge_type can also be used to implement different types of edge sampling, which will be more efficient?

[rusty1s]

Yeah, in that case you are basically free to start sampling from any edge in your graph (which may be of different type as well, i.e., edge_type does not need to point to a single index only).

[ccoverflow]

Thank you very much for your advice. I'll give it a try.

[ccoverflow]

@rusty1s My "HeteroData" has a label property on the edge of each type, where label values are of two types, 0 and 1. After I use "data.to_homogeneous()" how do I add the label properties of each type of edge into converted labels of the same composition?

[rusty1s]

Sorry for late reply. It's hard for me to understand your issue. Do you have a small example to illustrate? In the end label should just be concatenated across edge types when calling to_homogeneous().