Overview

A typical way of starting your escript script myscript.py is with the escript command[*]:
escript myscript.py
as already shown in section 1.2[*]. In some cases it can be useful to work interactively e.g. when debugging a script, with the command
escript -i myscript.py
This will execute myscript.py and when it completes (or an error occurs), a python prompt will be provided. To leave the prompt press Control-d.

To start escript using four threads (eg. if you use a multi-core processor) you can use

escript -t 4 myscript.py
This will require escript to be compiled for OpenMP [18].

To start escript using MPI [14] with $ 8$ processes you use

escript -p 8 myscript.py
If the processors which are used are multi-core processors or multi-processor shared memory architectures you can use threading in addition to MPI . For instance to run $ 8$ MPI processes with using $ 4$ threads each, you use the command
escript -p 8 -t 4 myscript.py
In the case of a super computer or a cluster, you may wish to distribute the workload over a number of nodes[*]. For example, to use $ 8$ nodes, with $ 4$ MPI processes per node, write
escript -n 8 -p 4 myscript.py
Since threading has some performance advantages over processes, you may specify a number of threads as well.
escript -n 8 -p 4 -t 2 myscript.py
This runs the script on $ 8$ nodes, with $ 4$ processes per node and $ 2$ threads per process.

esys@esscc.uq.edu.au