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 should be the same as for given by
get.edgelist. This is ignored for the unweighted
algorithm.
algorithm
The algorithm to use for
calculation. unweighted can be used for unwieghted graphs,
and prim runs Prim's algorithm for weighted graphs.
...
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.)
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.