NAME

       mplrs - Convert between representations of convex polyhedra (parallel version).

SYNOPSIS

                      mpirun  -np num_proc mplrs infile [outfile] [option...]

DESCRIPTION

       A polyhedron can be described by a list of inequalities (H-representation) or as by a list of its
       vertices and extreme rays (V-representation).  lrs is a C program that converts a H-representation of a
       polyhedron to its V-representation, and vice versa.  These problems are known respectively at the vertex
       enumeration and convex hull problems.

USAGE

       The number of processors num_proc specified to mpirun should be 4 or higher Unlike lrs (1), mplrs does
       not support options after the end statement of the input file.

   OPTIONS
       mplrs supports the following options.
           -id <initial depth> [2] the depth of the original tree search to populate the job queue L
           -maxc <maxcobases>[50 (*scale)] a producer stops and returns all subtrees that are not leaves to L
           after generating  maxc nodes
           -maxd <depth>[0] a producer returns all subtrees that are not leaves at depth maxd. Zero if not used
           -lmin <int>[3] if job queue |L|<np*lmin then the maxd parameter is set for all producers
           -lmax <int>[lmin] if job queue |L|>np*lmax then then maxc is replaced by maxc*scale
           -scale <int>[100]used by lmax
           -hist <file>store parallelization data in <file> for use by gnuplot, see below
           -temp <prefix>[/tmp/] store a temporary file for each process. Should be specified if /tmp not
           writeable. Using " -temp  ./ " will write temporary files to the current directory
           -freq <file> store frequency data in <file> for use by gnuplot, see below
           -stop <stopfile>  terminate mplrs if a file with name <stopfile> is created in the current directory
           -checkp <checkpoint file> if mplrs is terminated by -stop or -time then it can be restarted using
           this <checkpoint file> and -restart
           -restart <checkpoint file> restart mplrs using previously created <checkpoint file>. If used with
           -checkp file names should be different!
           -time <seconds> terminate mplrs after <seconds> of elapsed time
           -countonly don't output vertices/rays/facets, just count them
           -maxbuf <n>[500] controls maximum size of worker output buffers
           -stopafter <n> exit after approximately <n> cobases have been computed (no guarantee about how many
           vertices/rays/facets computed)
           -redund perform redundancy check of input file (also see redund )
       The parameters -hist and -freq give interesting information about the degree of parallelization.

EXAMPLE

       Input file mp5.ine is run with 8 processors. The output file mp5.mplrs is in the distribution. This
       produced 378 subtrees that were enumerated in parallel using 6 producer cores,  1 core controlling the
       run and 1 core collecting the output.

                 mai20% mpirun -np 8 mplrs mp5.ine mp5.mplrs
                 *mplrs:lrslib v.6.0 2015.7.13(lrsgmp.h)8 processes
                 *Copyright (C) 1995,2015, David Avis   avis@cs.mcgill.ca
                 *Input taken from mp5.ine
                 *Output written to: mp5.mplrs
                 *Starting depth of 2 maxcobases=50 maxdepth=0 lmin=3 lmax=3 scale=100
                 *Phase 1 time: 0 seconds.
                 *Total number of jobs: 378, L became empty 4 times
                 *Totals: vertices=32 rays=0 bases=9041 integer-vertices=16
                 *Elapsed time: 1 seconds.
                 2.285u 0.137s 0:01.86 129.5%    0+0k 0+9976io 36pf+0w

SEE ALSO

       lrs(1), lrslib(1)

July 2020                                           2020.7.28                                           MPLRS(1)