AnalysisTree

Important note on AnalysisTree versions

Current version is development version!

Last tested version: v2.2.1

Last release version: v.1.0.9

Different MAJOR version means incompatible API changes. Neither API nor data compatibility is preserved between MAJOR versions.

Since v2.2.1 old infra implementation is kept for the sake of code compatibility until the next MAJOR infra release.

Doxygen documentation:

https://heavyionanalysis.github.io/AnalysisTree/

General information

This is a dataformat to store information in configurable objects. Basic objects are:

Track (momentum)
Particle (momentum and PID)
Hit (position and signal)
Module (id and signal)
EventHeader (vertex position)
DataHeader (common information for all events)

Additionaly to mandatory information, each object can contain any number of integer, floating or boolean fields. Information about all fields in all branches is stored in Configuration object.

Installation

ROOT6 is needed for installation. Version compiled with c++17 flag is preferred, otherwise CMAKE_CXX_STANDARD flag needs to be implicitly specified (see below).

git clone https://github.com/HeavyIonAnalysis/AnalysisTree.git
cd AnalysisTree
mkdir build install
cd build
source /path/to/your/thisroot.sh
cmake -DCMAKE_INSTALL_PREFIX=../install ../
make -j install

List of CMake options:

To apply the flag use -D{Name}={value}, for example, if you want to compile using c++11:

cmake -DCMAKE_CXX_STANDARD=11 ../

Name	Default value	Possible values
CMAKE_BUILD_TYPE	RELEASE	RELEASE/DEBUG
CMAKE_CXX_STANDARD	17	11/14/17
AnalysisTree_BUILD_TESTS	OFF	ON/OFF
AnalysisTree_BUILD_EXAMPLES	ON	ON/OFF
AnalysisTree_BUILD_EXPERIMENTAL	OFF	ON/OFF

Reading AnalysisTree

Loading AnalysisTree libraries

First of all you need to load AnalysisTree libraries into your system. Usually, the path to libraries is added to LD_LIBRARY_PATH:

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/path/to/AnalysisTree/install/lib/

After that one can open ROOT session and load libraries:

root -l
gSystem->Load("libAnalysisTreeBase.so")

Reading files from ROOT session

Open a ROOT-file and check its content:

root -l
[0] gSystem->Load("libAnalysisTreeBase.so")
[1] gSystem->Load("libAnalysisTreeInfra.so")
[2] AnalysisTree::Chain t("filename.root", "tree_name")

Print the information about AnalysisTree structure:

t.Print()

You should see something like:

Draw any field you like with all TTree::Draw operations:

t.Draw("BranchName.FieldName")
t.Draw("log(BranchName.FieldName) * sin(BranchName.OtherFieldName)")
t.Draw("log(BranchName.FieldName) : sin(BranchName.OtherFieldName)")
 ...

For a QA of the file(s) please use the dedicated package AnalysisTreeQA:

https://github.com/HeavyIonAnalysis/AnalysisTreeQA

Reading file with ROOT macro/executable

Follow the instructions in class examples/UserTaskRead.{hpp,cpp}

Simple example of macro to read file:

auto* chain = new Chain("filename.root", "tree_name");
auto rec_particles = chain->GetBranch("RecParticles");
auto rec2sim_particles = chain->GetMatching("RecParticles", "SimParticles");
auto rec_pT = rec_particles.GetField("pT");

for (long i_event = 0; i_event < 10; ++i_event) {
    chain->GetEntry(i_event);
    for(int i=0; i<rec_particles.size(); ++i){
        auto pT = rec_particles[i][rec_pT];
        std::cout << pT << std::endl;
    }
}

Creating your own AnalysisTree

Follow the instructions in class examples/UserTaskWrite.{hpp,cpp}

Known problems (features)

BranchConfig::GetFieldId() is slow -> should not be used for every event/track/hit/module

eugene274/AnalysisTree