graph.Graph

[IvarStefansson]

I find one usage only. Can it be replaced with networkx functionality?

[keileg]

The Graph class is used to find disconnected clusters of cells during splitting of nodes (there will be two clusters for a standard fracture node, three for a T-intersection etc.). This can also be done by the method connected_components from networkx.

It turns out we have already done that change for the main splitting routine some years ago, see L779 in split_grid.py. The old graph class is used only in a hidden option to visualize the split grid with an offset in the nodes (function duplicate_nodes_with_offset in split_grid). Ideally, I should have seen this when searching for candidates for deprecation, but as mentioned elsewhere, the whole folder is too untidy for me to get a proper overview.

Options:

1. Leave as is.
2. Deprecate the visualization option. This will get rid of the graph class, and the last ~300 lines in split_grid
3. Update the visualization procedure to use networkx. Ideally, we should get rid of the parallel functions to duplicate nodes, but it is hard to estimate the work needed here. I do not recall the history, but suspect that there use to be a single function prior to the introduction of networkx, and that some combination of implementation complexity, convenience and laziness on my part led to the function not being updated.

Option 2 is by far the most convenient one, but I have no feeling for whether the offset option is being used. What do you think?

[IvarStefansson]

I vote for 2 or 3. If I am to provide a more thorough evaluation, I think we should discuss. Is there reason to believe that the answer could be influenced by the fact that we're planning to revive the propagation work?

[keileg]

@IvarStefansson Let's discuss this in person.

[keileg]

Resolution:

1. The graph class is deprecated, DEPR: Marked the Graph class for future deletion #1429
2. A rework of the relevant parts of split_grid is outlined in Revisit functionality for visualization of splitting of grids #1428