Ordering {RBGL}R Documentation

Compute vertex ordering for an undirected graph

Description

Compute vertex ordering for an undirected graph

Usage

cuthill.mckee.ordering(g)
minDegreeOrdering(g, delta=0)
sloan.ordering(g, w1=1, w2=2)

Arguments

g an instance of the graph class with edgemode “undirected”
delta Multiple elimination control variable. If it is larger than or equal to zero then multiple elimination is enabled. The value of delta specifies the difference between the minimum degree and the degree of vertices that are to be eliminated.
w1 1st Heuristical weight for the Sloan algorithm
w2 2nd Heuristical weight for the Sloan algorithm

Details

According to the documentations on these algorithms in Boost Graph Library:

The goal of the Cuthill-Mckee (and reverse Cuthill-Mckee) ordering algorithm is to reduce the bandwidth of a graph by reordering the indices assigned to each vertex.

The minimum degree ordering algorithm is a fill-in reduction matrix reordering algorithm.

The goal of the Sloan ordering algorithm is to reduce the profile and the wavefront of a graph by reordering the indices assigned to each vertex.

The goal of the King ordering algorithm is to reduce the bandwidth of a graph by reordering the indices assigned to each vertex.

See documentations on these algorithms in Boost Graph Library for more details.

Value

cuthill.mckee.ordering returns a list with elements:
reverse cuthill.mckee.ordering the vertices in the new ordering
original bandwidth bandwidth before reordering vertices
new bandwidth bandwidth after reordering of vertices
minDegreeOrdering return a list with elements:
inverse_permutation the new vertex ordering, given as the mapping from the new indices to the old indices
permutation the new vertex ordering, given as the mapping from the old indices to the new indices
sloan.ordering returns a list with elements:
sloan.ordering the vertices in the new ordering
bandwidth bandwidth of the graph after reordering
profile profile of the graph after reordering
maxWavefront maxWavefront of the graph after reordering
aver.wavefront aver.wavefront of the graph after reordering
rms.wavefront rms.wavefront of the graph after reordering

Author(s)

Li Long <li.long@isb-sib.ch>

References

Boost Graph Library by Siek et al.

See Also

Examples

coex <- fromGXL(file(system.file("XML/dijkex.gxl",package="RBGL"), open="r"))
coex <- ugraph(coex)
cuthill.mckee.ordering(coex)
minDegreeOrdering(coex)
sloan.ordering(coex)

[Package RBGL version 1.10.0 Index]