==Gadget Compilation Walkthrough==
This page describes how to compile your own [[http://www.mpa-garching.mpg.de/galform/gadget/index.shtml|Gadget]] and libraries at CHPC.
Before doing anything it is recommended that you create an installation directory (e.g installations) on your /export/home/username/ directory. This will help you avoid any super user conflicts. For the rest of this walkthrough I will refer to /export/home/username/installations/ as PATHINSTALL.
  *Prerequisites
    *[[http://www.gnu.org/software/gsl/|Gnu Scientific Library]] version 1.15 or above.
    *[[http://www.fftw.org/download.html|Fast Fourier Transform in the West]] version 2.1.5 is required for Gadget2. Do not use a later version.
    *[[http://www.hdfgroup.org/ftp/lib-external/
szip/2.1/src/szip-2.1.tar.gz|SZIP]] version 2.1 or above.
    *[[http://www.hdfgroup.org/ftp/HDF5/prev-releases/|HDF5]] version 1.6 is required. Do not use a later version here.
  *First, add these lines in your startup file .profile:<code>
. /etc/profile.d/modules.sh
module load sunstudio
module load clustertools </code>
These lines will help you to load openmpi and other tools that are required to compile and run Gadget. It is also recommended to add them to your job script.
  *Compile GSL by following these steps: 
    *./configure --prefix=/PATHINSTALL
    *make
    *make install
  *Compile FFTW-2.1.5 by following these steps:
    *./configure --prefix=/PATHINSTALL --enable-type-prefix --enable-mpi
    *make
    *make install
    *make clean
    *./configure --prefix=/PATHINSTALL --enable-float --enable-type-prefix --enable-mpi
    *make 
    *make install
 **Note that only FFTW-2.xx can be used because version 3.xx does not work with Gadget2.**
  *Compile HDF5 by following these steps:
First build SZIP by following these steps
    *./configure --prefix=/PATHINSTALL --enable-shared=no --enable-static=yes
    *make
    *make install
After building SZIP build HDF5 by following these steps
    *./configure -prefix=/PATHINSTALL
    *make
    *make install
 **Note that you need to use HDF5 version 1.6.x to avoid the latest changes in the HDF5 API.**
  *Now compile GADGET by following the following steps:
    *Find the Makefile and add the "CHPC" SYSTYPE on the list of SYSTYPEs listed and add this code <code> 
ifeq ($(SYSTYPE),"CHPC")
CC       =  mpicc
OPTIMIZE =  -O3
GSL_INCL =  -I/PATHINSTALL/include
GSL_LIBS =  -L/PATHINSTALL/lib  -Wl,"-R /PATHINSTALL/lib"
FFTW_INCL=  -I/PATHINSTALL/include
FFTW_LIBS=  -L/PATHINSTALL/lib
MPICHLIB =
HDF5INCL =  -I/PATHINSTALL/include
HDF5LIB  =  -L/PATHINSTALL/lib -lhdf5
endif
</code>
  *make
**GADGET is now compiled and you can test it by using one of the examples that come with Gadget download. You can also download a pdf version of this walkthrough {{mygadgetwalkthrough.pdf | here}}**