NAME
pscotch_dgord - compute sparse matrix orderings in parallel
SYNOPSIS
pscotch_dgord [options] [gfile] [ofile] [lfile]
DESCRIPTION
The pscotch_dgord program computes, in a parallel way, an ordering of a
source graph representing the pattern of some symmetric sparse matrix.
Source graph file gfile is either a centralized graph file, or a set of
files representing fragments of a distributed graph. The resulting
ordering is stored in file ofile. Eventual logging information (such as
the one produced by option -v) is sent to file lfile. When file names
are not specified, data is read from standard input and written to
standard output. Standard streams can also be explicitely represented
by a dash ’-’.
When the proper libraries have been included at compile time, dgord can
directly handle compressed graphs, both as input and output. A stream
is treated as compressed whenever its name is postfixed with a
compressed file extension, such as in ’brol.grf.bz2’ or ’-.gz’. The
compression formats which can be supported are the bzip2 format
(’.bz2’), the gzip format (’.gz’), and the lzma format (’.lzma’, on
input only).
pscotch_dgord bases on implementations of the MPI interface to spread
work across the processing elements. It is therefore not likely to be
run directly, but instead through some launcher command such as mpirun.
OPTIONS
-h Display some help.
-mmfile
Save column block mapping data to file mfile.
-ostrat
Use distributed ordering strategy strat (see PT-Scotch user’s
manual for more information).
-rpnum Set root process for centralized files (default is 0).
-ttfile
Save partitioning tree data to file tfile.
-V Display program version and copyright.
-vverb Set verbose mode to verb. It is a set of one of more characters
which can be:
s strategy information.
t timing information.
EXAMPLE
Run pscotch_dgord on 5 processing elements to reorder matrix graph
brol.grf and save the resulting ordering to file brol.ord.
$ mpirun -np 5 pscotch_dgord brol.grf brol.ord
Run pscotch_dgord on 5 processing elements to reorder the distributed
matrix stored on graph fragment files brol5-0.grf to brol5-4.grf, and
save the resulting ordering to file brol.ord (see dgscat(1) for an
explanation of the ’%p’ and ’%r’ sequences in names of distributed
graph fragments).
$ mpirun -np 5 pscotch_dgord brol%p-%r.grf brol.ord
SEE ALSO
pscotch_dgtst(1), pscotch_dgscat(1), scotch_gmk_hy(1), scotch_gord(1).
PT-Scotch user’s manual.
AUTHOR
Francois Pellegrini <francois.pellegrini@labri.fr>
June 01, 2008 pscotch_dgord(1)