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gmap(1)			     Scotch user's manual		       gmap(1)

       gmap, gpart - compute static mappings and partitions sequentially

       gmap [options] [gfile] [tfile] [mfile] [lfile]

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

       The  gmap  program computes, in a sequential way, a static mapping of a
       source graph onto a target graph.

       The gpart program is a simplified interface  to	gmap,  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, gmap only accepts variable-sized target architectures.

       Source graph file gfile can only	be a centralized graph file. For gmap,
       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.  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
       written to standard output. Standard streams can	 also  be  explicitely
       represented by a	dash '-'.

       When  the proper	libraries have been included at	compile	time, gmap and
       gpart can directly handle compressed graphs, both as input and  output.
       compressed file extension, such as in  'brol.grf.bz2'  or  '-.gz'.  The
       compression  formats  which  can	 be  supported	are  the  bzip2	format
       input only).

       -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.

	      It is exclusive with the -m option.

       -h     Display some help.

	      Use  sequential mapping strategy strat (see Scotch user's	manual
	      for more information).

       -q     (for gpart)

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

       -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.

       Target architectures represent graphs  onto  which  source  graphs  are
       mapped.	In  order  to  speed-up	 the obtainment	of target architecture
       topological properties during the computation of	mappings, some classi-
       cal  topologies are algorithmically coded into the mapper itself. These
       topologies are consequently simply defined by their code	name, followed
       by their	dimensional parameters:

       cmplt dim
	      unweighted complete graph	of size	dim.

       cmpltw dim w0 w1	... wdim-1
	      weighted complete	graph of size size and of respective loads w0,
	      w1, ..., wdim-1.

       hcub dim
	      hypercube	of dimension dim.

       leaf hgt	n0 w0 ... nhgt-1 whgt-1
	      tree-leaf	graph of height	 hgt  with  (n0	 times	n1  times  ...
	      nhgt-1) vertices,	with inter-cluster link	weights	of w0, w1, ...

       mesh2D dimX dimY
	      2D mesh of dimX times dimY nodes.

       mesh3D dimX dimY	dimZ
	      23 mesh of dimX times dimY times dimZ nodes.

       torus2D dimX dimY
	      2D torus of dimX times dimY nodes.

       torus3D dimX dimY dimZ
	      3D torus of dimX times dimY times	dimZ nodes.

       Other target topologies can be created from their source	graph descrip-
       tion by using the amk_grf(1) command. In	this case, the target descrip-
       tion will begin with the	code name deco.

       Mappings	are represented	by as many lines as there are vertices in  the
       source graph. Each of these lines is made of two	figures: the number of
       the vertex (or its label	if source graph	vertices are labeled) and  the
       index of	the target vertex to which it has been assigned. Target	vertex
       indices range from 0 to the number of vertices in the target  architec-
       ture (that is, the number of parts) minus one.

       This  block of lines is always preceded by the number of	such lines. In
       most cases, since full mappings are requested, the number of  lines  is
       equal to	the number of vertices in the source graph.

       Run  gpart  to compute a	partition into 7 parts of graph	'brol.grf' and
       save the	resulting ordering to file ''.

	   $ gpart 7 brol.grf

       Run gmap	to compute a partition,	into 3 parts of	respective weights  1,
       2  and  4,  of  graph 'brol.grf'	and save the resulting mapping to file
       ''. The dash '-'	standard file name is used so that the	target
       architecture  description  is read from the standard input, through the
       pipe, as	provided by the	'echo' shell command.

	   $ echo "cmpltw 3 1 2	4" | gmap brol.grf -

       amk_grf(1), acpl(1), gmtst(1), dgmap(1).

       Scotch user's manual.

       Francois	Pellegrini <>

			      September	01, 2011		       gmap(1)


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