// Copyright CERN and copyright holders of ALICE O2. This software is

// distributed under the terms of the GNU General Public License v3 (GPL

// Version 3), copied verbatim in the file "COPYING".

//

// See http://alice-o2.web.cern.ch/license for full licensing information.

//

// In applying this license CERN does not waive the privileges and immunities

// granted to it by virtue of its status as an Intergovernmental Organization

// or submit itself to any jurisdiction.

#include "Framework/runDataProcessing.h"

#include "Framework/AnalysisTask.h"

#include <TFile.h>

#include <TH1F.h>

using namespace o2;

using namespace o2::framework;

// This is a very simple example showing how to iterate over tracks

// and operate on them.

// FIXME: this should really inherit from AnalysisTask but

// we need GCC 7.4+ for that

struct ATask {

void process(aod::Tracks const& tracks)

{

// FIXME: to see some output, we create the histogram

// for every timeframe. In general this is not the way it

// should be done.

auto hPhi = new TH1F("phi", "Phi", 100, 0, 2 * M_PI);

auto hEta = new TH1F("eta", "Eta", 100, 0, 2 * M_PI);

for (auto& track : tracks) {

auto phi = asin(track.snp()) + track.alpha() + M_PI;

auto eta = log(tan(0.25 * M_PI - 0.5 * atan(track.tgl())));

hPhi->Fill(phi);

hEta->Fill(eta);

}

TFile f("result1.root", "RECREATE");

hPhi->SetName("Phi");

hPhi->Write();

hEta->SetName("Eta");

hEta->Write();

}

};

WorkflowSpec defineDataProcessing(ConfigContext const& cfgc)

{

return WorkflowSpec{

adaptAnalysisTask<ATask>(cfgc, TaskName{"track-collection-iteration-tutorial"})};

}