#include "TGraphErrors.h"
#include "TGraph.h"
#include "TF1.h"
#include "TCanvas.h"

void example05(){

	TVirtualFitter::SetDefaultFitter("Minuit");

	TGraphErrors *data = new TGraphErrors("dataset2.dat");
	TF1 *myModel = new TF1("oscillation","[0]*exp(-[1]*x)*sin([2]*x)^2"); 
	myModel->SetParameters(9.,1./100.,1./15.);
	data->Fit(myModel);

	gMinuit->SetErrorDef(1); // just to show, since it starts
	TGraph *cont01_1s = (TGraph*) gMinuit->Contour(100,0,1);
	TGraph *cont02_1s = (TGraph*) gMinuit->Contour(100,0,2);
	TGraph *cont12_1s = (TGraph*) gMinuit->Contour(100,1,2);

	gMinuit->SetErrorDef(4);
	TGraph *cont01_2s = (TGraph*) gMinuit->Contour(100,0,1);
	TGraph *cont02_2s = (TGraph*) gMinuit->Contour(100,0,2);
	TGraph *cont12_2s = (TGraph*) gMinuit->Contour(100,1,2);


	TCanvas *canvas = new TCanvas("canvas","My Fit",1000,500);
	canvas->Divide(2,2);

	canvas->cd(1);
	cont01_2s->SetFillColor(kOrange);
	cont01_1s->SetFillColor(kBlue);
	cont01_2s->Draw("AF");	
	cont01_1s->Draw("F same");	

	canvas->cd(3);
	cont02_2s->SetFillColor(kOrange);
	cont02_1s->SetFillColor(kBlue);
	cont02_2s->Draw("AF");	
	cont02_1s->Draw("F same");	

	canvas->cd(4);
	cont12_2s->SetFillColor(kOrange);
	cont12_1s->SetFillColor(kBlue);
	cont12_2s->Draw("AF");	
	cont12_1s->Draw("F same");	

	double cl = 0.95;
	int N=100;
	double xmin = 0.;
	double xmax = 35.;

	canvas->cd(2);
	TGraphErrors *band = new TGraphErrors(N);
	for (int i=0;i<N;i++) band->SetPoint(i, i*(xmax-xmin)/(N-1.), 0);
	(TVirtualFitter::GetFitter())->GetConfidenceIntervals(band,cl);
	band->SetFillColor(kOrange-2);
	band->Draw("A3");

	data->SetMarkerStyle(kFullCircle);
	data->SetMarkerColor(kBlue+2);
	data->Draw("PZ same");

}