%%cpp -d
#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooGaussian.h"
#include "RooProdPdf.h"
#include "RooAddPdf.h"
#include "RooMinimizer.h"
#include "RooFitResult.h"
#include "RooPlot.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "TH1.h"
using namespace RooFit;

RooRealVar x("x", "x", -20, 20);

RooRealVar mean("mean", "mean of g1 and g2", 0);
RooRealVar sigma_g1("sigma_g1", "width of g1", 3);
RooGaussian g1("g1", "g1", x, mean, sigma_g1);

RooRealVar sigma_g2("sigma_g2", "width of g2", 4, 3.0, 6.0);
RooGaussian g2("g2", "g2", x, mean, sigma_g2);

RooRealVar frac("frac", "frac", 0.5, 0.0, 1.0);
RooAddPdf model("model", "model", RooArgList(g1, g2), frac);

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

std::unique_ptr<RooAbsReal> nll{model.createNLL(*data)};

RooMinimizer m(*nll);

m.setVerbose(true);

m.migrad();

std::unique_ptr<RooArgSet>{model.getParameters(x)}->Print("s");

m.setVerbose(false);

m.hesse();

sigma_g2.Print();

m.minos(sigma_g2);

sigma_g2.Print();

std::unique_ptr<RooFitResult> fitResult{m.save()};

RooPlot *frame = m.contour(frac, sigma_g2, 1, 2, 3);
frame->SetTitle("Minuit contour plot");

fitResult->Print("v");

mean = 0.3;

m.migrad();
m.hesse();
frac.Print();

sigma_g2.setConstant(true);

m.migrad();
m.hesse();
frac.Print();

new TCanvas("rf601_intminuit", "rf601_intminuit", 600, 600);
gPad->SetLeftMargin(0.15);
frame->GetYaxis()->SetTitleOffset(1.4);
frame->Draw();

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