#include <TH1F.h>
#include <TCanvas.h>
#include <TImage.h>

#include <iostream> 

/*

To compile : 
g++ -g -I/opt/root/include -pthread -m64 -fPIC -W -Wall -Wextra -Wconversion -Wdisabled-optimization -Wno-unused -Wall -Wshadow -Wextra -Wredundant-decls -L/opt/root/lib -lGpad -lHist -lGraf -lGraf3d -lTree -lRint -lPostscript -lMatrix -lPhysics -lMathCore -lRIO -lNet -lThread -lCore -lCint -lm -ldl ex_drawclonepad.cpp

To run : 
./a.out

To valgrind : 
valgrind --suppressions=$ROOTSYS/etc/valgrind-root.supp --log-file=valgrind-drawclonepaddelete.output  --leak-check=full --tool=memcheck --show-reachable=no ./a.out


*/

int main(int argc, char *argv[]) {

  // create a tcanvas with pads, draw a h1 in a pad
  TCanvas* c1 = new TCanvas("test1");
  TH1F h1("h1", "h1", 100, 0, 99);
  c1->cd();
  h1.Draw();

  TCanvas* c2 = new TCanvas("test2");
  TH1F h2("h2", "h2", 100, 0, 99);
  c2->cd();
  h2.Draw();

  TImage *image1 = TImage::Create();
  TImage *image2 = TImage::Create();
  image1->FromPad(c1);
  image2->FromPad(c2);
  image1->Append(image2, "/");
  image1->WriteImage("test2.png", TImage::kPng);
  image1->Append(image2, "+");
  image1->WriteImage("test3.png", TImage::kPng);

}