Explains how to compile difx on the ozstar cluster

1. Load Dependencies.  This can be done either on the command line or in a 
   bash script.

module load ipp/2018.2.199
module load gcc/9.2.0
module load openmpi/4.0.2
module load gsl/2.5
module load python/3.7.4
module load astropy/4.0.1-python-3.7.4
module load numpy/1.18.2-python-3.7.4
module load matplotlib/3.2.1-python-3.7.4
module load scipy/1.4.1-python-3.7.4
module load pgplot/5.2.2
module load libpng/1.6.37


2. Check out difx

This command will check out the lasest unreleased version of the software
svn co https://svn.atnf.csiro.au/difx/virtualtrunk

This command will check out the latest tagged realese
svn co https://svn.atnf.csiro.au/difx/master_tags/DiFX-2.6.1

3. Modify setup file

A few enviroment variables will need to be changed for compilation to work on ozstar. These are all defined in the setup.bash file  (it's located here if you check out virtual trunk /virtualtrunk/setup.bash)

DIFXROOT point to a directory where the difx binaries will be installed
export DIFXROOT = /path/to/install/location

These enviroment variables point difx to various dependencies that are on ozstar 
export PGPLOTDIR=/apps/skylake/software/compiler/gcc/9.2.0/pgplot/5.2.2
export IPPROOT=/apps/skylake/software/core/ipp/2018.2.199/compilers_and_libraries_2018.2.199/linux/
export DIFXMPIDIR=/apps/skylake/software/OpenMPI/4.0.2-GCC-9.2.0/

4. Compile DiFX 

   Simply run the script ./install-difx and then difx should be ready to go!