void JEC_fit_Uncertainty(int N)

{

TF1 *func[1000];

TFile *inf = new TFile("L3Graphs_test_Icone5.root");

TGraphErrors *g = (TGraphErrors*)inf->Get("Correction_vs_CaloPt");

TGraphErrors *vg[1000];

int i,k;

double x[20],y[20],ex[20],ey[20];

double vx[20],vy[20],vex[20],vey[20];

for(i=0;i<g->GetN();i++)

{

g->GetPoint(i,x[i],y[i]);

ex[i]=g->GetErrorX(i);

ey[i]=g->GetErrorY(i);

}

TRandom *rnd = new TRandom();

rnd->SetSeed(0);

for(k=0;k<N;k++)

{

for(i=0;i<g->GetN();i++)

{

vx[i] = rnd->Gaus(x[i],ex[i]);

//vx[i] = x[i];

vy[i] = rnd->Gaus(y[i],ey[i]);

vex[i] = ex[i];

vey[i] = ey[i];

}

vg[k] = new TGraphErrors(g->GetN(),vx,vy,vex,vey);

func[k] = new TF1("func","[0]+[1]/(pow(log10(x),[2])+[3])",1,2000);

func[k]->SetParameters(1,3,6,5);

vg[k]->Fit(func[k],"RQ");

}

TCanvas *c = new TCanvas("c","c");

gPad->SetLogx();

g->SetMarkerStyle(20);

g->SetMaximum(3.5);

g->Draw("AP");

for(k=0;k<N;k++)

{

func[k]->SetLineColor(5);

func[k]->SetLineWidth(1);

cout<<func[k]->GetChisquare()<<endl;

vg[k]->SetMarkerColor(2);

vg[k]->SetLineColor(2);

vg[k]->SetMarkerStyle(21);

//if (func[k]->GetChisquare()<0.1)

//vg[k]->Draw("sameP");

func[k]->Draw("same");

}

}