MST Extraction

After reweighting, Core-SG extracts a minimum spanning tree with Kruskal’s algorithm.

The MST is the graph-level artifact used to reconstruct the hierarchy. Through the estimator, the current wrapped object is exposed as minimum_spanning_tree_ after fit(X, k=...).

If the support graph is disconnected, MST extraction fails. This is most visible in algorithm="score-sg", where the approximate support graph is not silently repaired.