RCS $Id: README,v 1.5 1995/08/22 23:42:21 tuna Exp $

To make the Barnes executable:
------------------------------
1. If you're running on a network of workstations, be sure that you
   have PVM installed correctly and functioning.

2. Compile the CRL library in the directory "../../src" (see the user
   documentation in "../../doc" for details).

3. Type "make -f Makefile.CM5" to make the CM-5 Barnes executable.

     -- or --

   Edit Makefile.TCPUNIX and change the definitions for PVM_ROOT and
   PVM_ARCH to whatever is appropriate for your local system. Once
   you've done so, type "make -f Makefile.TCPUNIX" to make the
   TCP/UNIX Barnes executable.

4. If you're running this program with PVM and the executable isn't
   already in your path, be sure to create a soft link to the
   executable from the directory ~/pvm3/bin/$PVM_ARCH.

Running Barnes:
---------------
All versions of Barnes take two arguments: the number of processors on
which the user wishes to run and the number of bodies to use. The
desired number of processors must match the number available (except
on the CM-5, where the desired number of processors must be less than
or equal the number of processors available).

The following information is taken from the SPLASH-2 distribution; it
is included below for convenience:
-------------------------------------------------------------------------------

GENERAL INFORMATION:

The BARNES application implements the Barnes-Hut method to simulate
the interaction of a system of bodies (N-body problem). A general
description of the Barnes-Hut method can be found in:

  Singh, J. P. Parallel Hierarchical N-body Methods and Their
  Implications for Multiprocessors. PhD Thesis, Stanford University,
  February 1993.

The SPLASH-2 implementation allows for multiple particles to be stored
in each leaf cell of the space partition. A description of this
feature can be found in:

  Holt, C. and Singh, J. P. Hierarchical N-Body Methods on Shared
  Address Space Multiprocessors. SIAM Conference on Parallel
  Processing for Scientific Computing, Feb 1995, to appear.

RUNNING THE PROGRAM:

To see how to run the program, please see the comment at the top of
the file code.C, or run the application with the "-h" command line
option. The input parameters should be placed in a file and redirected
to standard input. Of the twelve input parameters, the ones which
would normally be varied are the number of particles and the number of
processors. If other parameters are changed, these changes should be
reported in any results that are presented.

The only compile time option, -DQUADPOLE, controls the use of quadpole
interactions during the force computation. For the input parameters
provided, the -DQUADPOLE option should not be defined. The constant
MAX_BODIES_PER_LEAF defines the maximum number of particles per leaf
cell in the tree. This constant also affects the parameter "fleaves"
in the input file, which controls how many leaf cells space is
allocated for. The higher the value of MAX_BODIES_PER_LEAF, the lower
fleaves should be. Both these parameters should be kept at their
default values for base SPLASH-2 runs. If changes are made, they
should be reported in any results that are presented.
