next | previous | forward | backward | up | top | index | toc | Macaulay2 website
EdgeIdeals :: getGoodLeafIndex

getGoodLeafIndex -- returns the index of an edge that is a good leaf

Synopsis

Description

A good leaf of hypergraph H is an edge L whose intersections with all other edges form a totally ordered set. It follows that L must have a free vertex. In the graph setting, a good leaf is an edge containing a vertex of degree one. The notion of a good leaf was introduced by X. Zheng in her Ph.D. thesis (2004).

i1 : R = QQ[a..g];
 
i2 : H = hyperGraph {b*c*d*e, a*b*c*d, c*d*f, d*g, e*f*g};
 
i3 : getGoodLeaf(H)

o3 = {a, b, c, d}

o3 : List
 
i4 : edges(H)

o4 = {{a, b, c, d}, {b, c, d, e}, {c, d, f}, {d, g}, {e, f, g}}

o4 : List
 
i5 : getGoodLeafIndex(H)

o5 = 0

See also

Ways to use getGoodLeafIndex :

For the programmer

The object getGoodLeafIndex is a method function.