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dgmap(1)		    PT-Scotch user's manual		      dgmap(1)

       dgmap, dgpart - compute static mappings and partitions in parallel

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

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

       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  ar-
       chitectures 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. Stan-
       dard 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 in-
       put 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

       -copt  Choose  default mapping strategy according to one	or several op-
	      tions 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.

	      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.

       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.

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

	   $ mpirun -np	5 dgpart 7 brol.grf

       Run dgpart on 5 processing elements to partition	into 7 parts the  dis-
       tributed	  graph	  stored   on  graph  fragment	files  brol5-0.dgr  to
       brol5-4.dgr, and	save the  resulting  mapping  to  file  (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

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

       PT-Scotch user's	manual.

       Francois	Pellegrini <>

				August 03, 2010			      dgmap(1)


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