NAME

       gord - compute sparse matrix orderings of graphs

SYNOPSIS

       gord [options] [gfile] [ofile] [lfile]

DESCRIPTION

       The  gord  program  computes,  in  a  sequential way, an ordering of a Scotch source graph
       representing the pattern of some symmetric sparse matrix.

       Source graph file gfile can only be a centralized graph file. 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,  gord  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').

OPTIONS

       -copt  Choose default ordering strategy according to one or several options among:

              b      enforce load balance as much as possible.

              q      privilege quality over speed (default).

              s      privilege speed over quality.

              t      enforce safety.

       -h     Display some help.

       -mmfile
              Save column block mapping data to file mfile.  Mapping  data  specifies,  for  each
              vertex, the index of the column block to which this vertex belongs.

       -ostrat
              Use  sequential  graph  ordering  strategy strat (see Scotch user's manual for more
              information).

       -ttfile
              Save partitioning tree data to file tfile. Partitioning tree  data  specifies,  for
              each  vertex,  the  index  of  the first vertex of the parent block of the block to
              which the vertex belongs. Altogether with the mapping data provided in file  mfile,
              it allows one to rebuild the separator tree of the nested dissection process.

       -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

       Reorder  matrix  graph brol.grf and save the resulting ordering to file brol.ord using the
       default sequential graph ordering strategy:

           $ gord brol.grf brol.ord

SEE ALSO

       dgord(1), gmk_hy(1), gtst(1).

       Scotch user's manual.

AUTHOR

       Francois Pellegrini <francois.pellegrini@labri.fr>

                                         23 November 2019                                 gord(1)