Ordering {RBGL} | R Documentation |
Compute vertex ordering for an undirected graph
cuthill.mckee.ordering(g) minDegreeOrdering(g, delta=0) sloan.ordering(g, w1=1, w2=2)
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 |
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. See documentations on these algorithms in Boost Graph Library for more details.
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 |
Li Long <li.long@isb-sib.ch>
Boost Graph Library by Siek et al.
coex <- fromGXL(file(system.file("XML/dijkex.gxl",package="RBGL"))) coex@edgemode <- "undirected" cuthill.mckee.ordering(coex) minDegreeOrdering(coex) sloan.ordering(coex)