Macaulay2 » Documentation
Packages » EdgeIdeals :: isolatedVertices
next | previous | forward | backward | up | index | toc

isolatedVertices -- returns all vertices not contained in any edge

Synopsis

Description

A vertex of a hypergraph is called isolated if it is not contained in any edges. Vertices in a hypergraph that are contained in an edge of size one are not considered to be isolated.

i1 : R = QQ[a,b,c,d,e];
 
i2 : G = graph {a*b,c*d}

o2 = Graph{"edges" => {{a, b}, {c, d}}  }
           "ring" => R
           "vertices" => {a, b, c, d, e}

o2 : Graph
 
i3 : isolatedVertices G

o3 = {e}

o3 : List
 
i4 : H = hyperGraph {a*b,c}

o4 = HyperGraph{"edges" => {{a, b}, {c}}     }
                "ring" => R
                "vertices" => {a, b, c, d, e}

o4 : HyperGraph
 
i5 : isolatedVertices H

o5 = {d, e}

o5 : List

See also

Ways to use isolatedVertices :

For the programmer

The object isolatedVertices is a method function.