draw.cxx

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/// \file
/// \ingroup tutorial_v7
///
/// \macro_code
///
/// \date 2015-03-22
/// \warning This is part of the ROOT 7 prototype! It will change without notice. It might trigger earthquakes. Feedback
/// is welcome!
/// \author Axel Naumann <axel@cern.ch>

/*************************************************************************
 * Copyright (C) 1995-2015, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

#include "Rtypes.h"

R__LOAD_LIBRARY(libROOTHistDraw);

#include "ROOT/THist.hxx"
#include "ROOT/TCanvas.hxx"
#include "ROOT/TColor.hxx"
#include "ROOT/TDirectory.hxx"

void draw()
{
   using namespace ROOT;

   // Create the histogram.
   Experimental::TAxisConfig xaxis("x", 10, 0., 1.);
   Experimental::TAxisConfig yaxis("y", {0., 1., 2., 3., 10.});
   auto pHist = std::make_shared<Experimental::TH2D>(xaxis, yaxis);

   // Fill a few points.
   pHist->Fill({0.01, 1.02});
   pHist->Fill({0.54, 3.02});
   pHist->Fill({0.98, 1.02});
   pHist->Fill({1.90, 1.02});
   pHist->Fill({0.75, -0.02});

   // Register the histogram with ROOT: now it lives even after draw() ends.
   Experimental::TDirectory::Heap().Add("hist", pHist);

   // Create a canvas to be displayed.
   auto canvas = Experimental::TCanvas::Create("Canvas Title");
   canvas->Draw(pHist)->SetLineColor(Experimental::TColor::kRed);

   canvas->Show();
}