A subgraph of a connected graph is a minimum spanning tree
if it is tree, and the sum of its edge weights are the minimal among
all tree subgraphs of the graph. A minimum spanning forest of a graph
is the graph consisting of the minimum spanning trees of its
components.
Numeric algorithm giving the weights of the edges in
the graph. The order is determined by the edge ids. This is ignored
if the unweighted algorithm is chosen
algorithm
The algorithm to use for
calculation. unweighted can be used for unwieghted graphs,
and prim runs Prim's algorithm for weighted graphs.
If this is NULL then igraph tries to select the algorithm
automa
...
Additional arguments, unused.
Value
A graph object with the minimum spanning forest. (To check that it is
a tree check that the number of its edges is vcount(graph)-1.)
The edge and vertex attributes of the original graph are preserved in
the result.
concept
Minimum spanning tree
Details
If the graph is unconnected a minimum spanning forest is returned.
References
Prim, R.C. 1957. Shortest connection networks and some
generalizations Bell System Technical Journal, 37 1389--1401.