%%cpp -d
#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooGaussian.h"
#include "RooChebychev.h"
#include "RooAddPdf.h"
#include "RooExtendPdf.h"
#include "RooFitResult.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "RooPlot.h"
using namespace RooFit ;

RooRealVar x("x","x",0,11) ;

RooRealVar mean("mean","mean of gaussians",5) ;
RooRealVar sigma1("sigma1","width of gaussians",0.5) ;
RooRealVar sigma2("sigma2","width of gaussians",1) ;

RooGaussian sig1("sig1","Signal component 1",x,mean,sigma1) ;
RooGaussian sig2("sig2","Signal component 2",x,mean,sigma2) ;

RooRealVar a0("a0","a0",0.5,0.,1.) ;
RooRealVar a1("a1","a1",0.2,0.,1.) ;
RooChebychev bkg("bkg","Background",x,RooArgSet(a0,a1)) ;

RooRealVar sig1frac("sig1frac","fraction of component 1 in signal",0.8,0.,1.) ;
RooAddPdf sig("sig","Signal",RooArgList(sig1,sig2),sig1frac) ;

x.setRange("signalRange",4,6) ;

RooRealVar nsig("nsig","number of signal events in signalRange",500,0.,10000) ;
RooRealVar nbkg("nbkg","number of background events in signalRange",500,0,10000) ;

RooAddPdf  model("model","(g1+g2)+a", RooArgList(bkg,sig), RooArgList(nbkg,nsig)) ;

std::unique_ptr<RooDataSet> data{model.generate(x,1000)};



auto canv = new TCanvas("Canvas", "Canvas", 1500, 600);
canv->Divide(3,1);

canv->cd(1);

RooAddPdf model1(model);
std::unique_ptr<RooFitResult> r{model1.fitTo(*data,Save(), PrintLevel(-1))};
r->Print() ;

RooPlot * frame = x.frame(Title("Full range fitted"));
data->plotOn(frame);
model1.plotOn(frame, VisualizeError(*r));
model1.plotOn(frame);
model1.paramOn(frame);
frame->Draw();

canv->cd(2);
x.setRange("left",  0., 4.);
x.setRange("right", 6., 10.);

RooAddPdf model2(model);
std::unique_ptr<RooFitResult> r2{model2.fitTo(*data, Range("left,right"), Save(), PrintLevel(-1))};
r2->Print();


RooPlot * frame2 = x.frame(Title("Fit in left/right sideband"));
data->plotOn(frame2);
model2.plotOn(frame2, VisualizeError(*r2));
model2.plotOn(frame2);
model2.paramOn(frame2);
frame2->Draw();

canv->cd(3);
x.setRange("leftToMiddle",  0., 5.);

RooAddPdf model3(model);
std::unique_ptr<RooFitResult> r3{model3.fitTo(*data, Range("leftToMiddle"), Save(), PrintLevel(-1))};
r3->Print();


RooPlot * frame3 = x.frame(Title("Fit from left to middle"));
data->plotOn(frame3);
model3.plotOn(frame3, VisualizeError(*r3));
model3.plotOn(frame3);
model3.paramOn(frame3);
frame3->Draw();

canv->Draw();

%jsroot on
gROOT->GetListOfCanvases()->Draw()