rh1_twoscales.cxx

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/// \file
/// \ingroup tutorial_rcanvas
///
/// This macro generates two RH1D, fills them and draw in RCanvas.
/// Second histogram uses enables "secondy" attribute to draw separate Y axis on right side
///
/// \macro_image (rcanvas_js)
/// \macro_code
///
/// \date 2021-05-17
/// \warning This is part of the ROOT 7 prototype! It will change without notice. It might trigger earthquakes. Feedback is welcome!
/// \author Sergey Linev <s.linev@gsi.de>
 
/*************************************************************************
 * Copyright (C) 1995-2021, 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 "ROOT/RHist.hxx"
#include "ROOT/RHistDrawable.hxx"
#include "ROOT/RFrameTitle.hxx"
#include "ROOT/RCanvas.hxx"
#include "ROOT/RPad.hxx"
#include "TRandom.h"
 
// macro must be here while cling is not capable to load
// library automatically for outlined function see ROOT-10336
R__LOAD_LIBRARY(libROOTHistDraw)
 
using namespace ROOT::Experimental;
 
void rh1_twoscales()
{
   // Create the histogram.
   RAxisConfig xaxis(25, 0., 10.);
   auto pHist1 = std::make_shared<RH1D>(xaxis);
   auto pHist2 = std::make_shared<RH1D>(xaxis);
 
   for (int n=0;n<1000;n++)
      pHist1->Fill(gRandom->Gaus(3,0.8));
 
   for (int n=0;n<3000;n++)
      pHist2->Fill(gRandom->Gaus(7,1.2));
 
   // Create a canvas to be displayed.
   auto canvas = RCanvas::Create("RH1 with two Y scales");
 
   // histograms colors
   auto col1 = RColor::kRed, col2 = RColor::kBlue;
 
   // default draw option
   canvas->Draw<RFrameTitle>("Two independent Y axes for histograms");
   auto draw1 = canvas->Draw(pHist1);
   draw1->line.color = col1;
   draw1->line.width = 2;
   auto draw2 = canvas->Draw(pHist2);
   draw2->secondy = true;
   draw2->line.color = col2;
   draw2->line.width = 4;
 
   canvas->GetFrame()->y.ticks.color = col1;
   canvas->GetFrame()->y2.ticks.color = col2;
 
   canvas->SetSize(800, 600);
   canvas->Show();
}