Gabriele Cosmo
115 lines
3.8 KiB
Markdown
115 lines
3.8 KiB
Markdown
\page Examples_HepMC Category "eventgenerator/HepMC"
|
|
|
|
This directory contains examples for using HepMC as an interface with
|
|
various Monte Carlo event generators, such as PYTHIA.
|
|
It also include an example for demonstrating MC truth handling with HepMC.
|
|
|
|
## Requirements for external software packages
|
|
|
|
### HepMC
|
|
- Tested version : 2.06.09
|
|
- http://lcgapp.cern.ch/project/simu/HepMC/
|
|
|
|
Note: examples were tested only on Linux with gcc.
|
|
|
|
### PYTHIA
|
|
- Tested version 6.4.26
|
|
- URL: http://www.thep.lu.se/~torbjorn/Pythia.html
|
|
|
|
|
|
## Examples HepMCEx01 and HepMCEx02
|
|
|
|
### class HepMCG4Interface
|
|
This class is derived from G4VPrimaryGenerator, and is a base class
|
|
for primary generation via HepMC object.
|
|
|
|
protected members:
|
|
|
|
- virtual HepMC::GenEvent* GenerateHepMCEvent() \n
|
|
Implement this method in his/her own concrete class.
|
|
An empty event will be created in default.
|
|
|
|
- void HepMC2G4(const HepMC::GenEvent* hepmcevt, G4Event* g4event) \n
|
|
service method for conversion from HepMC::GenEvent to G4Event
|
|
|
|
- virtual G4bool CheckVertexInsideWorld(const G4ThreeVector& pos) const \n
|
|
We have to take care for the position of primaries because
|
|
primary vertices outside the world volume give rise to G4Exception.
|
|
If the default implementation is not adequate, an alternative
|
|
can be implemented in your own class.
|
|
|
|
public members:
|
|
- virtual void GeneratePrimaryVertex(G4Event* anEvent) \n
|
|
The default behavior is that a single HepMC event generated by
|
|
GenerateHepMCEvent() will be converted to G4Event through HepMC2G4().
|
|
|
|
### class HepMCG4AsciiReader / HepMCG4AsciiReaderMessenger (derived from HepMCG4Interface)
|
|
This derived class is for reading primary information from
|
|
an Ascii file generated by HepMC.
|
|
|
|
### class HepMCG4PythiaInterface / HepMCG4AsciiReaderMessenger (derived from HepMCG4Interface)
|
|
This derived class is for directly calling PYTHIA functions.
|
|
Users can set parameters, initialize, generate, and terminate
|
|
by command line operation.
|
|
|
|
### Macros in examples
|
|
|
|
- hepmc_pygen.in \n
|
|
process PYTHIA events(H->4mu) generated at every event.
|
|
|
|
- hepmc_ascii.in \n
|
|
read pregenerated events from HepMC Ascii file (data/example_MyPythia.dat).
|
|
|
|
### Installation
|
|
|
|
- 1. Download and install HepMC from: \n
|
|
http://lcgapp.cern.ch/project/simu/HepMC/ \n
|
|
and define the environment variable:
|
|
```
|
|
HEPMC_DIR the path to HepMC installation.
|
|
```
|
|
|
|
- 2. Download the PYTHIA6 source file from the PYTHIA6 download site:\n
|
|
http://www.hepforge.org/downloads/pythia6
|
|
|
|
- 2A. With CMake: Build pythia6 library
|
|
|
|
For a convenience a CMake file for building Pythia6 library from
|
|
the source is provided in
|
|
examples/extended/eventgenerator/CMakeLists.txt.pythia6.
|
|
Build the pythia6 library following the instructions in this file
|
|
and then define the environment variables:
|
|
```
|
|
PYTHIA6 the path where pythia6 library is installed
|
|
PYTHIA6_VERSION the pythia version
|
|
```
|
|
|
|
- 2B. With GNUmake: Define the environment variables: \n
|
|
```
|
|
PYTHIA6 the path to pythia-versionX.f source code
|
|
PYTHIA6_VERSION the pythia version
|
|
```
|
|
|
|
e.g. If you download pythia-6.4.26.f.gz and unzip it in $HOME,
|
|
then you have to set:
|
|
export PYTHIA6=$HOME
|
|
export PYTHIA6_VERSION="6.4.26"
|
|
|
|
pythia6 will be then compiled together with example code.
|
|
|
|
- 3. Compilation:\n
|
|
Then the examples are compiled in a standard way, see \ref README_HowToRun.
|
|
|
|
### Examples
|
|
|
|
See more details in \ref ExampleHepMCEx01 and \ref ExampleHepMCEx02.
|
|
|
|
### Notes
|
|
|
|
We attached a sample HepMC Ascii data file, "data/example_MyPythia.dat",
|
|
which contains 10 PYTHIA events created by "data/example_MyPythia.cxx".
|
|
|
|
## Example MCTruth
|
|
|
|
Application \ref ExampleMCTruth demonstrating handling of Monte-Carlo truth information through the HepMC package.
|