if(smallEventID==-1||mediumEventID==-1||largeEventID==-1){// when we get to the selected event, fill histograms and write data
AliESDtrack*track=static_cast<AliESDtrack*>(fESD->GetTrack(i));// get a track (type AliESDtrack) from the event
if(!track)continue;// if we failed, skip this track
Double_tMass=track->M();// returns the pion mass, if the particle can't be identified properly
Double_tEnergy=track->E();// Returns the energy of the particle given its assumed mass, but assumes the pion mass if the particle can't be identified properly.
Double_tPx=track->Px();
Double_tPy=track->Py();
Double_tPt=track->Pt();// transversal momentum, in case we need it
Double_tPz=track->Pz();
Double_tCharge=track->Charge();
if(smallEventID==-1){
// Add VERTEX (x, y, z), MASS, CHARGE and MOMENTUM (x, y, z) to esd-detail.dat file
s_detail<<Vx<<" "<<Vy<<" "<<Vz<<" ";
s_detail<<Mass<<" "<<Charge<<" ";
s_detail<<Px<<" "<<Py<<" "<<Pz<<endl;
}
if(mediumEventID==-1){
// Add VERTEX (x, y, z), MASS, CHARGE and MOMENTUM (x, y, z) to esd-detail.dat file
m_detail<<Vx<<" "<<Vy<<" "<<Vz<<" ";
m_detail<<Mass<<" "<<Charge<<" ";
m_detail<<Px<<" "<<Py<<" "<<Pz<<endl;
}
if(largeEventID==-1){
// Add VERTEX (x, y, z), MASS, CHARGE and MOMENTUM (x, y, z) to esd-detail.dat file
l_detail<<Vx<<" "<<Vy<<" "<<Vz<<" ";
l_detail<<Mass<<" "<<Charge<<" ";
l_detail<<Px<<" "<<Py<<" "<<Pz<<endl;
fHistPt->Fill(Pt);// plot the pt value of the track in a histogram
fHistMass->Fill(Mass);
}
}
for(Int_ti(0);i<iTracks;i++){// loop ove rall these tracks
AliESDtrack*track=static_cast<AliESDtrack*>(fESD->GetTrack(i));// get a track (type AliESDtrack) from the event
if(!track)continue;// if we failed, skip this track
// Add track number and corresponting pt to eventsdetail txt file
This project has the purpose of generating a 3D animation of an ALICE particle collision event, inside the LHC, using data obtained from CERN's Open Data Portal, which makes ESDs - Event Summary Data files, that contain information about such events - open and available for analysis.
ESD files regarding the ALICE experiment can be found on http://opendata.cern.ch/search?page=1&size=20&experiment=ALICE, and they should be processed using the Aliroot software, as indicated by the Instructions section below
The software that makes the animation is Blender, which is free and open source. Blender's 2.79b version should be downloaded for this project, and can be found on https://www.blender.org/download/releases/2-79/
The animation making can be summarized in three basic steps:
1) Downloading of an ESD file (for example, any file on this list: http://opendata.cern.ch/record/1102);
2) Processing of ESD file using Aliroot macros (as indicated further);
3) Run code to generate Blender animation using the ESD processing results.
The code for step 3 can be found in the Blender_animation repository: https://git.cta.if.ufrgs.br/ALICE-open-data/alice-blender-animation/tree/ParticleTypes
# Sample macros for processing AliESDs from CERN Open Data Portal
## Requirements
...
...
@@ -34,7 +51,7 @@ alienv enter AliPhysics/latest-aliroot5-user
```bash
aliroot runAnalysis.C
```
Results will be saved on two text files: `events_summary.txt` and `events_detail.txt`.
Results will be saved on three text files: `s-esd-detail.dat`, for an event with a 'small' number of tracks; `m-esd-detail.dat`, for an event with a medium number of tracks; `l-esd-detail.dat`, for an event with a very large number of tracks.
Breno Rilho Lemos authorede6fcd0dd