StokesFlow.run() show "Exception: Your network is clustered, making Ax = b ill-conditioned"

[eromanga233]

Dear professor:
When calculating the absolute permeability of digital cores, I use pn = op.io.network_from_porespy(net.network) to construct a network in openpnm. However, it always goes as 'Exception: Your network is clustered, making Ax = b ill-conditioned'. I am wondering what makes this error happen and how can I fix it ?

[jgostick]

This issue comes up a lot so I wrote a detailed example that should help: https://openpnm.org/examples/reference/networks/managing_clustered_networks.html