Scotch Brand 5.1.10 - Manual (Page 60)

cond1 |cond2
Logical or operator. The result of the condition is true if cond1 or cond2
are true, or both.
cond1 &cond2
Logical and operator. The result of the condition is true only if both
cond1
and cond2 are true.
!cond
Logical not operator. The result of the condition is true only if cond is
false.
var relop val
Relational operator, where var is a graph variable, val is either a graph
variable or a constant of the type of variable var , and relop is one of ’<’,
’=’, and ’>’. The graph variables are listed below, along with their types.
deg
The average degree of the current graph. Float.
edge
The number of arcs (which is twice the number of edges) of the
current graph. Integer.
load
The overall vertex load (weight) of the current graph. Integer.
load0
The vertex load of the first subset of the current bipartition of the
current graph. Integer.
vert
The number of vertices of the current graph. Integer.
method [{parameters}]
Bipartitioning method. For bipartitioning methods that can be parametrized,
parameter settings may be provided after the method name. Parameters must
be separated by commas, and the whole list be enclosed between curly braces.
The currently available graph bipartitioning methods are the following.
b Band method. This method builds a band graph of given width around the
current frontier of the graph to which it is applied, and calls a graph biparti-
tioning strategy to refine the equivalent bipartition of the band graph. Then,
the refined frontier of the band graph is projected back to the current graph.
This method, presented in [8], was created to reduce the cost of vertex sepa-
rator refinement algorithms in a multi-level context, but it improves partition
quality too. The same behavior is observed for graph bipartitioning. The
parameters of the band bipartitioning method are listed below.
bnd=strat
Set the graph bipartitioning strategy to be used on the band graph.
org=strat
Set the fallback graph bipartitioning strategy to be used on the original
graph if the band graph strategy could not be used. The three cases
which require the use of this fallback strategy are the following. First, if
the separator of the original graph is empty, which makes it impossible
to compute a band graph. Second, if any part of the band graph to be
built is of the same size as the one of the original graph. Third, if the
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