[Date Index]
[Thread Index]
[Author Index]
Adding an edge to a directed cyclic graph
*To*: mathgroup at smc.vnet.net
*Subject*: [mg88908] Adding an edge to a directed cyclic graph
*From*: "W_Craig Carter" <ccarter at mit.edu>
*Date*: Wed, 21 May 2008 14:48:43 -0400 (EDT)
Sorry to ask a question that probably has an answer in the
Combinatorica book; I've just purchased it and waiting for delivery.
I am teaching myself discrete math by learning Combinatorica. Is there
an obvious way to add an edge to a directed graph and have
the edges renumbered associated with the cyclic order? The number of
vertices are fixed.
This seems like a common thing to do; so before embarking on my own
code to do this, I am hoping I am missing an obvious built-in.
For example:
Needs["Combinatorica`"]
(*c6 is the cycle in which I'd like to insert and edge*)
c6 = Cycle[6, Type -> Directed]
ShowGraph[c6, VertexNumber -> True, EdgeLabel -> True,
EdgeLabelColor -> Darker[Orange], BaseStyle -> Large]
(*here I hope to add a sub-loop to replace the edge going from 4-5*)
modc6 = AddEdges[
DeleteEdge[c6, {4, 5}],
{
{{4, 5}, EdgeColor -> Green},
{{5, 4}, EdgeColor -> Blue},
{{4, 5}, EdgeColor -> Red}
}
]
(*the edge numbering no longer corresponds to the cycle index--what I
need is a "ReplaceEdge"*)
ShowGraph[modc6, VertexNumber -> True, EdgeLabel -> True,
EdgeLabelColor -> Darker[Orange], BaseStyle -> Large]
(*does anyone know an option to increase the "bowing angle" of the
Graphics for the subloop?*)
(*thanks*)
--
W. Craig Carter
Prev by Date:
**intersecting a hypercube and a hyperplane**
Next by Date:
**Re: Problems with ListPlot**
Previous by thread:
**Re: intersecting a hypercube and a hyperplane**
Next by thread:
**Re: Adding an edge to a directed cyclic graph**
| |