5.2. igraph_cohesion — Graph cohesion, this is the same as vertex connectivity.

5.2. `igraph_cohesion` — Graph cohesion, this is the same as vertex connectivity.

int igraph_cohesion(const igraph_t *graph, igraph_integer_t *res,
		    igraph_bool_t checks);

This quantity was defined by White and Harary in “The cohesiveness of blocks in social networks: node connectivity and conditional density”, (Sociological Methodology 31:305--359, 2001) and it is the same as the vertex connectivity of a graph.

Arguments:

`graph`:	The input graph.
`res`:	Pointer to an integer variable, the result will be stored here.
`checks`:	Logical constant. Whether to check that the graph is connected and also the degree of the vertices. If the graph is not (strongly) connected then the cohesion is obviously zero. Otherwise if the minimum degree is one then the cohesion is also one. It is a good idea to perform these checks, as they can be done quickly compared to the vertex connectivity calculation itself. They were suggested by Peter McMahan, thanks Peter.

Returns:

Error code.

Time complexity: O(|V|^4), |V| is the number of vertices. In practice it is more like O(|V|^2), see igraph_maxflow_value().