NAME

       dgmap, dgpart - compute static mappings and partitions in parallel

SYNOPSIS

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

       dgpart [options] [nparts] [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 shortcut of dgmap for computing partitions of a source graph.

       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', on input only).

       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

       -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.

       -h     Display some help.

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

       -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 5.1.0), 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>

                                                 August 03, 2010                                        dgmap(1)