NAME
  dgmap, dgpart - compute static mappings and partitions in parallel

SYNOPSIS
  dgmap [options] [gfile] [tfile] [mfile] [lfile]

  dgpart [options] [nparts/pwght] [gfile] [mfile] [lfile]

DESCRIPTION
  The dgmap program computes, in a parallel way, a static mapping of a
  source graph onto a target graph.

  The dgpart program is a simplified interface to dgmap, which
  performs graph partitioning instead of static mapping. Consequently,
  the desired number of parts has to be provided, in lieu of the
  target architecture. When using the program for graph clustering,
  the number of parts turns into maximum cluster weight.

  The -b and -c options allow the user to set preferences on the
  behavior of the mapping strategy which is used by default. The -m
  option allows the user to define a custom mapping strategy.

  The -q option turns the programs into graph clustering programs. In
  this case, dgmap only accepts variable-sized target architectures.

  Source graph file gfile is either a centralized graph file, or a set
  of files representing fragments of a distributed graph. For dgmap,
  the target architecture file tfile describes either algorithmically-coded
  topologies such as meshes and hypercubes, or decomposition-defined
  architectures created by means of the amk_grf(1) program. See
  gmap(1) for a description of target architectures. The resulting
  mapping is stored in file mfile. 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, dgmap
  and dgpart 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').

  dgmap and dgpart base on implementations of the MPI interface to
  spread work across the processing elements. They are therefore not
  likely to be run directly, but instead through some launcher command
  such as mpirun.

OPTIONS
  -bval     Set maximum load imbalance ratio for graph partitioning
              or static mapping. When programs are used as clustering
	      tools, this parameter sets the maximum load imbalance
	      ratio for recursive bipartitions. Exclusive with
              the -m option.

  -copt     Choose default mapping 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.
              x  enforce scalability.

              It is exclusive with the -m option.


  -h          Display some help.

  -mstrat   Use parallel mapping strategy strat (see
              PT-Scotch user's manual for more information).

  -q          (for dgpart)
  -qpwght   (for dgmap)
              Use the programs as graph clustering tools instead of
              static mapping or graph partitioning tools. For dgpart,
              the number of parts will become the maximum cluster
              weight. For dgmap, this number pwght has to be passed
              after the option.

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

  -V          Display program version and copyright.

  -vverb    Set verbose mode to verb. It is a set of one of more
              characters which can be:
              m  mapping information.
              s  strategy information.
              t  timing information.

NOTE
  At the time being (version 5.1), dgmap cannot compute full static
  mappings as gmap(1) does, but only partitions (that is, mappings
  onto unweighted or weighted complete graphs). Target architectures
  other than the 'cmplt' and 'wcmplt' ones will lead to an error
  message.

EXAMPLES
  Run dgpart on 5 processing elements to compute a partition into 7
  parts of graph brol.grf and save the resulting ordering to file brol.map.

    $ mpirun -np 5 dgpart 7 brol.grf brol.map

  Run dgpart on 5 processing elements to partition into 7 parts the
  distributed graph stored on graph fragment files brol5-0.dgr to
  brol5-4.dgr, and save the resulting mapping to file brol.map (see
  dgscat(1) for an explanation of the '%p' and '%r' sequences in names
  of distributed graph fragments).

    $ mpirun -np 5 dgpart 7 brol%p-%r.dgr brol.map

SEE ALSO
  dgtst(1), dgscat(1), amk_grf(1), acpl(1), gmap(1), gmtst(1).

  PT-Scotch user's manual.

AUTHOR
  Francois Pellegrini <francois.pellegrini@labri.fr>
