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)