Julia bindings for the Geant4 particle transportation toolkit. It is using CxxWrap.jl package to wrap C++ types and functions to Julia. Since the Geant4 toolkit is rather large and complex, writing the wrapper code by hand is not really an option. For this, we use the package WrapIt that automates the generation of the wrapper code making use of the clang library.
The Geant4.jl package does no require any special installation. Stable releases are registered into the Julia general registry, and therefore can be deployed with the standard Pkg Julia package manager.
To use and play with the examples on this package, the user can clone this repository and setup a complete Julia environment with:
git clone https://github.com/JuliaHEP/Geant4.jl.gitjulia --project=Geant4.jl/examples -e 'import Pkg; Pkg.instantiate()'
Import the Geant4 module. All the wrapped Geant4 classes are exported since they are prefixed by G4 minimizing the chances of a name clash with other Julia symbols.
julia> using Geant4
julia> runManager = G4RunManager()
**************************************************************
Geant4 version Name: geant4-11-01-patch-01 [MT] (10-February-2023)
Copyright : Geant4 Collaboration
References : NIM A 506 (2003), 250-303
: IEEE-TNS 53 (2006), 270-278
: NIM A 835 (2016), 186-225
WWW : http://geant4.org/
**************************************************************
Geant4.G4RunManagerAllocated(Ptr{Nothing} @0x00007f9fcb6f9c50)
julia> methodswith(G4RunManager, supertypes=true)
[1] convert(t::Type{G4RunManager}, x::T) where T<:G4RunManager in Geant4 at /Users/mato/.julia/packages/CxxWrap/IdOJa/src/CxxWrap.jl:676
[2] AbortEvent(arg1::Union{CxxWrap.CxxWrapCore.CxxRef{<:G4RunManager}, Union{CxxWrap.CxxWrapCore.SmartPointer{T2}, T2} where T2<:G4RunManager}) in Geant4 at /Users/mato/.julia/packages/CxxWrap/IdOJa/src/CxxWrap.jl:618
...
[94] rndmSaveThisRun(arg1::Union{CxxWrap.CxxWrapCore.CxxRef{<:G4RunManager}, Union{CxxWrap.CxxWrapCore.SmartPointer{T2}, T2} where T2<:G4RunManager}) in Geant4 at /Users/mato/.julia/packages/CxxWrap/IdOJa/src/CxxWrap.jl:618
julia> v = GetVersionString(runManager)
ConstCxxRef{G4String}(Ptr{G4String} @0x00007ffed34df2d8)
julia> String(v)
" Geant4 version Name: geant4-11-01-patch-01 [MT] (10-February-2023)"Note that class methods are called with the object instance as first argument. In C++ the GetVersionString method would be called as runManager->GetVersionString() while in Julia it is called as GetVersionString(runManager). Thanks to the Julia multi-dispatch we do not need to prefix the methods with the module name Geant4.GetVersionString(runManager), even for very common function names such as mag.
julia> v = G4ThreeVector(1,2,3)
Geant4.CLHEP!Hep3VectorAllocated(Ptr{Nothing} @0x00007f9fcaf2a710)
julia> mag(v)
3.7416573867739413The Geant4 system of units is in separate sub-module. You can import it with
using using Geant4.SystemOfUnits
Only some basic units are always exported. If you need additional ones, you can do for example:
import Geant4.SystemOfUnits:tesla, candela
To run the tests execute julia --project=. test/runtests.jl
For the time being there are only some basic examples plus some more to illustrate some of the features
This is most basic example using a more Geant4 native interface.
To run it, execute julia --project=examples examples/basic/B1/B1.j or execute the notebook B1.ipynb
Basic example using a sensitive detector to collect 'hits'.
To run it, execute julia --project=examples examples/basic/B2/B2a.jl
Example using the Geant4 built-in scoring mechanism.
To run it, execute julia --project=examples examples/basic/B2/B2a.jl
This example comes from extended/electromagnetic/TestEm3 example. Since it requires additional packages such as FHist and Plots it has its own Julia environment in the folder examples/TestEm3. It is based on user actions.
To run it, execute julia --project=examples -i examples/TestEm3/TestEm3.jl
Example in a notebook format similar to RE03 but with different primary particle generator (MedicalBeam) and using the scoring mechanism. Plots are produced after each run.
Example script and in a notebook format of a bubble chamber in which we display the particle tracks for an event that passes the trigger. To run it, execute `julia --project=ext/G4Vis/examples ext/G4Vis/examples/HBC30/HBC30.jl``
The project includes additional functionality for visualization under the directory ext/G4Vis as an extension. The extension is activated if the following modules are included in the project ("Makie", "Colors", "StaticArrays", "Rotations", "LinearAlgebra"), which is the same if the project is set to ext/G4Vis/examples. To run the examples do:
julia --project=ext/G4Vis/examples -i ext/G4Vis/examples/B1vis.jlNote the option-ito keep the interactive session open.- The notebook
ext/G4Vis/examples/Solids.ipynbhave all the type of solids that can be defined with Geant4
We use the Geant4 libraries and data from the binary package Geant4_jll, which has been produced with the BinaryBuilder recipe. The wrapper library is downloaded from the binary package Geant4_julia_jll.
In order to re-generate locally new C++ wrapper code we need to have wrapit installed, which itself requires libclang to be installed. If the executable is not found (not in the PATH), we can use the wrapper code that is already pre-generated and distributed with this package.
- what C++ classes get wrapped is controlled by the file
gen/Geant4.wit. See the documentation of WrapIt for the details. - run the
gen/build.jlscript generate the wrapper code (if wrapit found) and build the wrapper library.
Once the wrapper code is stabilized we can move the generated code to the repository Geant4_cxxwrap to regenerate the binary package Geant using the BinaryBuilder`.