Memory Issue when running CODEX_SpleenDataset

[Luchixiang]

Hi! Thanks for the great work. I'm trying to run the CODEX_SpleenDataset using your code. But I find it hard to load a (80000, 80000) matrix into the GPU. Training the model on the CPU is really slow. I'm wondering how you trained on this dataset. Did you try sparse tensor and GCN instead of DenseGCN?