Scotch Brand 5.1.10 - Manual (Page 45)

Since its main purpose is to provide orderings that exhibit high concurrency
for parallel block factorization, it comprises a nested dissection method [17],
but classical [39] and state-of-the-art [1, 47] minimum degree algorithms are
implemented as well. Ordering methods are used to define ordering strategies
by means of selection, grouping, and condition operators.
The -o option allows the user to define the ordering strategy. The -c option
allows the user to set preferences on the behavior of the ordering strategy
which is used by default.
Options
Since the program is devoted to experimental studies, it has many optional
parameters, used to test various execution modes. Values set by default will
give best results in most cases.
-cflags
Tune the default ordering strategy according to the given preference flags.
Some of these flags are antagonistic, while others can be combined. See
Section 7.3.1 for more information. The resulting strategy string can be
displayed by means of the -vs option.
b Enforce load balance as much as possible.
q Privilege quality over speed. This is the default behavior.
s Privilege speed over quality.
t Use only safe methods in the strategy.
-h Display the program synopsis.
-moutput mapping file
Write to output mapping file the mapping of mesh node vertices to col-
umn blocks. All of the separators and leaves produced by the nested
dissection method are considered as distinct column blocks, which may
be in turn split by the ordering methods that are applied to them. Dis-
tinct integer numbers are associated with each of the column blocks, such
that the number of a block is always greater than the ones of its prede-
cessors in the elimination process, that is, its leaves in the elimination
tree. The structure of mapping files is given in section 5.5.
When the coordinates of the node vertices are available, the mapping
file may be processed by program gout, along with the graph structure
that can be created from the source mesh file by means of the gmk
msh
program, to display the node vertex separators and supervariable
amalgamations that have been computed.
-ostrat
Apply ordering strategy strat. The format of ordering strategies is defined
in section 7.3.4.
-toutput tree file
Write to output tree file the structure of the separator tree. The data
that is written resembles much the one of a mapping file: after a first
line that contains the number of lines to follow, there are that many
lines of mapping pairs, which associate an integer number with every
node vertex index. This integer number is the number of the column
block which is the parent of the column block to which the node vertex
belongs, or −1 if the column block to which the node vertex belongs is
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