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)