NAME

       gmap, gpart - compute static mappings and partitions sequentially

SYNOPSIS

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

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

DESCRIPTION

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

       The gpart program is a shortcut of gmap for computing unweighted partitions  of  a  source
       graph.

       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 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, gmap and gpart 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).

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.

       -h     Display some help.

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

       -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

       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 classical 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, ... whgt-1.

       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 description by using the
       amk_grf(1) command. In this case, the target description will begin  with  the  code  name
       deco.

MAPPINGS

       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
       architecture (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.

EXAMPLES

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

           $ gpart 7 brol.grf brol.map

       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 'brol.map'. 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 - brol.map

SEE ALSO

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

       Scotch user's manual.

AUTHOR

       Francois Pellegrini <francois.pellegrini@labri.fr>

                                         August 03, 2010                                  gmap(1)