I've encountered a shape mismatch issue between synthetic features (feat_syn) and labels (labels_syn) when condensing the ogbn-arxiv dataset using a reduction rate of 0.0005. The method ensures each class is represented by at least one label, but the calculation feat_train * reduction_rate can lead to a discrepancy in the number of features and labels.
Probably consider using n = max(int(len(data.idx_train) * args.reduction_rate), labels_syn.shape[0]) to calculate the number of synthetic features?