nbody_sh1p.txt

mpi编程

    > * Reader for nbody_sh1p a parallel direct N-body code*

    Educational N-body integrator with a shared but variable time step
    (the same for all particles but changing in time), using the Hermite
    integration scheme (Hut, P. & Makino, M, 2003
    <http://www.artcompsci.org> in /The art of Computer Science/). The
    source code has been adapted for a parallel ring algorithm using the
    MPI <www-unix.mcs.anl.gov/mpi/mpich/> library.

        download latest source code of nbody_sh1p.tar.gz
        <nbody_sh1p.tar.gz> 

    nbody_sh1p.tar.gz contains the following files:
    README This file
    Makefile Makefile (requires MPI)
    nbody_sh1p.C The main parallel N-body code.
    pipe.C Routines to circulate data around in a ring. This is all
    reasonably standard MPI In fact, it is standard MPE, but repeated
    here for consistency and independence (original version of pipe.C
    <http://wotug.ukc.ac.uk/parallel/standards/mpi>)
    pipe.h Header file for pipe.C
    n24body.in An example input file for a 24-particle system
    n24body.out Output for the example input file (run on a single
    processor).

    Typical command line (generates : n24body.out)
    *%* nbody_sh1p < n24body.in > n24body.out

    28 November 2003
    Simon Portegies Zwart

    Version log:

        Version 1.0: Initial development by Put & Makino on 1 Jan 2002
        Version 2.0: Adopted for MPI by Portegies Zwart on 2 Okt 2003 
        Version 2.01: Bug fix and independent Makefile 
	              by Portegies Zwart on 25 Jun 2004

    > *Initial performance and timing analysis.*

    MPI N-body timing <./timing.jpg>

        Small timing test (perfomed by A. Gualandris) for 128, 256 and
        512 particles with up to 32 processors on the Blue (Boewulf)
        linux cluster at SARA <http://www.sara.nl>.
        These tests were run for 10 N-body time units for a Plummer
        model and a King model with W_0 = 12