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)