Rangesets would be a good alternative to represent group-item relationships:
They were presented at VIS 2021 as part of:
J. -T. Sohns, M. Schmitt, F. Jirasek, H. Hasse and H. Leitte,
"Attribute-based Explanation of Non-Linear Embeddings of High-Dimensional Data,"
in IEEE Transactions on Visualization and Computer Graphics, doi: 10.1109/TVCG.2021.3114870.
https://ieeexplore.ieee.org/abstract/document/9552929
Rangesets would be a good alternative to represent group-item relationships:
They were presented at VIS 2021 as part of:
The Rangeset implementation is available at: https://github.com/leitte/NoLiES/blob/main/Embedding/Rangeset.py