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.
Usage
mst(graph, weights = NULL, algorithm = NULL, ...)
Arguments
graph
The graph object to analyze.
weights
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 automatically: if the
...
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.
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.