Scotch Brand 5.1.10 - Manual (Page 66)

ordering strategy is then applied to the derived graph, and this ordering is
projected back to the nodes of the mesh. This method is here for evaluation
purposes only, as mesh ordering methods are generally more efficient than
their graph ordering counterpart.
strat=strat
Graph ordering strategy to apply to the associated graph.
7.3.5 Node separation strategy strings
A node separation strategy is made of one or several node separation methods,
which can be combined by means of strategy operators. Strategy operators are
listed below, by increasing precedence.
strat1 |strat2
Selection operator. The result of the selection is the best vertex separator of
the two that are obtained by the distinct application of strat1 and strat2 to
the current separator.
strat1 strat2
Combination operator. Strategy strat2 is applied to the vertex separator
resulting from the application of strategy strat1 to the current separator.
Typically, the first method used should compute an initial separation from
scratch, and every following method should use the result of the previous one
as a starting point.
(strat )
Grouping operator. The strategy enclosed within the parentheses is treated
as a single separation method.
/cond ?strat1 [:strat2];
Condition operator. According to the result of the evaluation of condition
cond
, either strat1 or strat2 (if it is present) is applied. The condition applies
to the characteristics of the current subgraph, and can be built from logical
and relational operators. Conditional operators are listed below, by increasing
precedence.
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 or node variable, val is either
a graph or node variable or a constant of the type of variable var , and
relop
is one of ’<’, ’=’, and ’>’. The graph and node variables are listed
below, along with their types.
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