This is with reference to the PR #6727 and is discussed in the comments in #5774.
Description
The current implementation of LabelPropagation, in semi_supervised module, creates directed k-NN graphs when the knn kernel is chosen.
One way to fix it is as shown in musically-ut/semi_supervised.
Steps to Reproduce / Expected Results / Actual Results
This is part of the reason I didn't submit it as a separate issue: it is difficult to come up with test cases which are obviously correct or incorrect.
However, none of the papers about semi-supervised learning cited in #6727 considers directed graphs. Using directed graphs has some obvious problems, like rendering parts of the graph completely unreachable, thus limiting the propagation of labels only from roots to descendants.
This is with reference to the PR #6727 and is discussed in the comments in #5774.
Description
The current implementation of
LabelPropagation, insemi_supervisedmodule, creates directed k-NN graphs when theknnkernel is chosen.One way to fix it is as shown in musically-ut/semi_supervised.
Steps to Reproduce / Expected Results / Actual ResultsThis is part of the reason I didn't submit it as a separate issue: it is difficult to come up with test cases which are obviously correct or incorrect.
However, none of the papers about semi-supervised learning cited in #6727 considers directed graphs. Using directed graphs has some obvious problems, like rendering parts of the graph completely unreachable, thus limiting the propagation of labels only from roots to descendants.