NDMETIS
Section: User Commands (1)
Updated: August 2020
Page Index
NAME
ndmetis  Computes a fillreducing ordering of the vertices of the graph using multilevel nested dissection.
SYNOPSIS
ndmetis
[
,options/]
,<filename>/
DESCRIPTION

Required parameters
 filename

Stores the graph to be partitioned.

Optional parameters

ctype=,string/

 Specifies the scheme to be used to match the vertices of the graph
during the coarsening.
The possible values are:
 rm

 Random matching
 shem

 Sorted heavyedge matching [default]

iptype=,string/ [applies only when ptype=,rb]/

 Specifies the scheme to be used to compute the initial bisection
of the graph.
The possible values are:
 edge

 Separator from an edge cut
 node

 Separator from a greedy nodebased strategy [default]

rtype=,string/

 Specifies the scheme to be used for refinement.
The possible values are:
 1sided

 1sided nodebased refinement [default]
 2sided

 2sided nodebased refinement

ufactor=,int/

 Specifies the maximum allowed load imbalance between the left and
right partitions during each bisection. The load imbalanced is
measured as the ratio of the 2*max(left,right)/(left+right), where
left and right are the sizes of the respective partitions.
A value of x indicates that the allowed load imbalance is 1+x/1000.
Default is 200, indicating a load imbalance of 1.20.

pfactor=,int/

 Specifies the minimum degree of the vertices that will be ordered
last. If the specified value is x>0, then any vertices with a degree
greater than 0.1*x*(average degree) are removed from the graph, an
ordering of the rest of the vertices is computed, and an overall
ordering is computed by ordering the removed vertices at the end
of the overall ordering.
Default value is 0, indicating that no vertices are removed

no2hop

 Specifies that the coarsening will not perform any 2hop matchings
when the standard matching fails to sufficiently contract the graph.

nocompress

 Specifies that the graph should not be compressed by combining
together vertices that have identical adjacency lists.

ccorder

 Specifies if the connected components of the graph should first be
identified and ordered separately.

niter=,int/

 Specifies the maximum number of iterations for the refinement
algorithms at each stage of the uncoarsening process. Default is 10.

nseps=,int/

 Specifies the number of different separators that it will compute at
each level of the nested dissection. The final separator that is used
is the smallest one. Default is 1.

nooutput

 Specifies that no ordering file should be generated.

seed=,int/

 Selects the seed of the random number generator.

dbglvl=,int/

 Selects the dbglvl.

help

 Prints this message.