Wishlist: Determine if a group of vertices forms a clique (is_clique, is_independent_set)

[szhorvat]

What is the feature or improvement you would like to see?

A function that determines if within a group of vertices, all pairs are connected (with one or more edges).

igraph_is_clique(const igraph_t *graph, igraph_vs_t vs, igraph_bool_t directed);

Similarly, there should be a function that checks that within a group of vertices, no pair is connected (but self-loops are still allowed).

igraph_is_independent_set(const igraph_t *graph, igraph_vs_t vs);

Use cases for the feature

• Useful helper for algorithm development
• Useful for teaching and exploration
• With igraph_vss_all(), provides a way to check if a graph is complete UPDATE: Already implemented as igraph_is_complete().

Related

• igraph_induced_subgraph_edges()

References

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