NAME

       dgtst - test the consistency of source graphs in parallel

SYNOPSIS

       dgtst [options] [gfile] [lfile]

DESCRIPTION

       The dgtst program checks, in a parallel way, the consistency of a Scotch source graph and,
       in case of success, outputs some statistics regarding edge weights,  vertex  weights,  and
       vertex degrees.

       It  produces  the  very  same  results  as  the  gtst(1)  program of the Scotch sequential
       distribution, but unlike this latter it can handle distributed graphs.

       Source graph file gfile is either a centralized graph file, or a set of files representing
       fragments  of a distributed graph. The resulting statistics are stored in file lfile. When
       file names are not specified, data is read from standard input  and  written  to  standard
       output. Standard streams can also be explicitly represented by a dash '-'.

       When  the  proper  libraries have been included at compile time, dgtst 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).

       dgtst  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.

       -rpnum Set root process for centralized files (default is 0).

       -V     Display program version and copyright.

EXAMPLE

       Run dgtst on 5 processing elements to test the consistency of graph brol.grf

           $ mpirun -np 5 dgtst brol.grf

       Run  dgord  on 5 processing elements to test the consistency of a distributed graph stored
       on graph fragment files brol5-0.dgr to brol5-4.dgr, 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 dgtst brol%p-%r.dgr brol.ord

SEE ALSO

       dgscat(1), gtst(1), dgord(1).

       PT-Scotch user's manual.

AUTHOR

       Francois Pellegrini <francois.pellegrini@labri.fr>

                                         August 03, 2010                                 dgtst(1)