2. Lab setup of software: Geant4
José A. Ramos Méndez, PhD.
University of California San Francisco

3. Requirements
The requirements vary from one OS system to others. But essentially one needs (either main package and developer libraries):
C++ and GLIBC
CMAKE
OpenGL
X11 libraries
EXPAT
Debian-based
apt-get install expat-dev
RedHat-based
yum install expat-devel
OSX
port install expat
4/26/2017
FCFM-BUAP, Puebla, Pue.

4. geant4.web.cern.ch
4/26/2017
FCFM-BUAP, Puebla, Pue.

5. Installation Create a directory named Geant4 in your home directory.
Uncompress Geant4 and the DATA files downloaded from the webpage
Create the directories: Geant4/geant4-build and Geant4/geant4-install
Inside Geant4/geant4-build do the follow:
cmake ../geant4.xxx.xxx -DGEANT4_BUILD_MULTITHREADED=ON
-DGEANT4_USE_OPENGL_X11=ON
-DGEANT4_USE_RAYTRACER_X11=ON
-DEXPAT_LIBRARY=/usr/lib/libexpat.so -DGEANT4_INSTALL_DATA=OFF
-DCMAKE_INSTALL_PREFIX=../geant4-install
Then: make -jN where N is the number of CPUs in your PC
Finally make install
4/26/2017
FCFM-BUAP, Puebla, Pue.

6. Installation Setup the environment variables:
For example if your Geant4 is at your $HOME/Geant4, then
export GEANT4=$HOME/Geant4
export Geant4_DIR=$GEANT4/geant4-install
export G4LEDATA=$GEANT4/G4EMLOW6.41
export G4NEUTRONHPDATA=$GEANT4/G4NDL4.5
export G4SAIDXSDATA=$GEANT4/G4SAIDDATA1.1
export G4NEUTRONXSDATA=$GEANT4/G4NEUTRONXS1.4
export G4LEVELGAMMADATA=$GEANT4/PhotonEvaporation3.1
export G4RADIOACTIVEDATA=$GEANT4/RadioactiveDecay4.2
Add those lines to ~/.bashrc; ~/.bash_profile
4/26/2017
FCFM-BUAP, Puebla, Pue.

7. Running user@user$ cd $GEANT4/geant4.xxx.xxx
cd examples/basic/B1
mkdir build
cd build
cmake ../
make -jN
./exampleB1 run1.mac
./exampleB1
4/26/2017
FCFM-BUAP, Puebla, Pue.

8. The command line and parallelism
4/26/2017
FCFM-BUAP, Puebla, Pue.

9. Running Let’s start with the example Geant4/basic/B1
./exampleB1
Idle> /run/beamOn 10
Like-Unix commands. Do not use in a macro.
cd, pwd - jump to a command directory and shows the path, respectively
ls - all available commands
history - used commands
?UICommand - shows the parameter of command UICommand
help UICommand - Provide detailed help, navigate it through keyboard
exit - Finalize simulation
4/26/2017
FCFM-BUAP, Puebla, Pue.

10. Multithreading In exampleB1.cc add
G4cout << “##### “ << G4Threading::GetNumberOfCores()
<< “ ####” << G4endl;
rebuild and execute. Then you can set
/run/numberOfThreads 4 Or
runManger->SetNumberOfThreads(
G4Threading::GetNumberOfCores() );
Modify run1.mac. Set verbosity to 0.
4/26/2017
FCFM-BUAP, Puebla, Pue.

11. Cluster Let’s play with the random generation seed. In exampleB1.cc
G4int myseed = G4UIcommand::ConvertToInt(argv[2]);
G4Random::setTheSeed(mySeed);
Rebuild and execute for different seeds
./exampleB1 run1.mac 2324
Everyone pick a ID number, we will use in each simulation.
Assign a seed number to each attendee. Let’s create our cluster.
4/26/2017
FCFM-BUAP, Puebla, Pue.