Instructions for running a SWAN model
-------------------------------------

Windows 7/8.1/10
----------------

*) Before running, first adapt the environment
   variable PATH by including the pathname of the
   directory where swan.exe can be found. This
   pathname can be specified through the category
   System of Control Panel, on the Advanced tab,
   click Environment Variables.

*) You may also need to add the directory path where
   bin of MPI is resided to PATH to have access to
   the command mpiexec.exe or mpirun.

*) Open a command prompt and change to the directory
   where your application is resided.

*) Execute the batch-file swanrun.bat as follows:

   swanrun SWAN-inputfile [nprocs]

   where SWAN-inputfile is the name of your inputfile
   without extension (it is assumed that the extension
   is '.swn') and 'nprocs' indicates how many processors
   need to be launched for a parallel MPI run (do not
   type the brackets; they just indicate that nprocs
   is optional). By default, nprocs=1.

   This script is also suited when no MPICH2 is available
   (of course, nprocs must be 1).

   This script is also suited for multi-core PC provided
   that SWAN source code with OpenMP directives is
   compiled. The parameter 'nprocs' must be set to 1.


UNIX or Linux
-------------

*) The name of the SWAN-executable must be swan.exe.
   Furthermore, adapt the environment variable PATH
   by including the pathname of the directory where
   this executable can be found.

*) Use the script swanrun. To execute this script, it
   will need to be executable first, so

   chmod +rx ./swanrun

*) This script can be used as follows:

   ./swanrun -input SWAN-inputfile [-omp n | -mpi n] [> swanout &]

   where SWAN-inputfile is the name of your inputfile
   without extension (it is assumed that the extension
   is '.swn') and n is the number of processors.
   The parameter '-omp n' specifies a parallel run on n
   threads using OpenMP. The parameter '-mpi n' specifies
   a parallel run on n cores using MPI. The parameter
   '-input' is obliged, whereas the parameters '-omp n' or
   '-mpi n' can be omitted (default: n=1).

   This script is also suited when no MPI is available
   (of course, n must be 1).

   You may redirect the output of swanrun to the file
   swanout (in this case). It is also possible to run
   your model in the background as indicated by the
   ampersand.

*) For a parallel MPI run, you may also need a machinefile
   that contains the names of the nodes in your parallel
   environment. Put one node per line in the file. You
   can specify a number followed by a colon after the node
   name to indicate how many processes to launch on the
   node. This is useful e.g., for multi-core processors.
   The run procedure will cycle through this list until
   all the requested processes are launched. Example file:

   node1
   node2:2
   node4
   node7:4