If you want a formatted (or easier-to-read) version of this file, scroll to the bottom of GramsSim/README.md for instructions. If you're reading this on github, then it's already formatted.
This directory contains utility scripts to help work with GramsSim inputs and outputs. Some of the programs are provided solely to teach programming concepts for folks new to:
- C++
- ROOT
- handling TTrees, both individually and as friends
- GDML (Geant4 geometry)
- HepMC3 (particle-physics file format)
For examples related to working with Geant4 and GramsG4, see GramsSim/mac.
-
The key example files require a dictionary to read
GramsSimoutput files. See GramsDataObj for details. -
If you add scripts/programs to this directory that require HepMC3, cfitsio, or healpix, be sure to edit the CMakeLists.txt file. This is to prevent those programs from being compiled on systems that don't have these libraries installed.
SimpleAnalysis.C - A simple example of how to look at the trees
produced by gramsg4 using a ROOT macro. Note how this macro depends
on GramsSim/rootlogon.C, which loads the
dictionary when you start an
interactive ROOT session.
SimpleAnalysis.py - A Python script that performs the
same function as SimpleAnalysis.C.
skyview.C - Another simple example. This creates a 3D histogram of the
primary particles in the GramsG4 output file.
skyview.py - A Python script that performs a similar
function as skyview.C.
dEdxExample.cc - An example of how to read a map-based branch in one
of the GramsSim output files. There are lots of detailed comments in
here, to point the way to users developing code for their own tasks.
dEdxExample.py - The same as above, in Python.
RadialDistance.py - A more realistic example of how to look at the
trees produced by gramsg4.
AllFilesExample.cc - An example of how to open
all the output files from all the GramsSim programs at once, set
them up as friend trees. This allows you to treat the entire
ensemble of GramsSim output files as a single structure. (As the
comments in the code warn, don't copy this blindly. Edit it down to
only read the files you need. Much of the code in the main loop serves
no useful purpose.)
AllFilesExample.py - The same as above, in Python.
BacktrackExample.cc - AllFileExample shows
how to use all the files at once to go through the GramsSim objects in
the "foward direction": tracks->hits->clusters->waveforms. This
program shows how to go in opposite direction:
waveforms->clusters->hits->tracks. Again, as the comments warn, think
about what you're copying; about half the code in the analysis loop
serves no useful purpose.
BacktrackExample.py - The same as above, in Python.
Hist2Text.C - Converts a ROOT histogram into the simple text format
used by Geant4's General Particle Source system. Any .root or .txt
files in this directory are used as example inputs and outputs for
Hist2Text.C.
gdmlsearch.cc - An example of how to use ROOT to search through a
geometry specified in GDML and extract information from it.
The following C++ programs are intended as simple examples of handling
event creation in HepMC3. Note that the examples in
${HepMC3_ROOT_DIR}/share/doc/HepMC3/examples are better illustrations,
but they don't necessarily produce outputs that are useful for
GramsG4.
The compiled programs are put into the bin/ sub-directory of your GramsG4 working/build directory. To execute them, you'll want something like:
# Go to your GramsG4 build directory
./bin/hepmc-grams-example
The programs are:
hepmc-grams-example - Creates a few example events "by hand" and
writes them to a file.
hepmc-convert - Converts one HepMC3-format file to another HepMC3
format. See the main README.md file for a list of available formats
and other notes.
example.hepmc3 - a file of a few events in HepMC3 format.