void frac_fit(){
double Ndata [] = {315239.0, 40524.1, 8625.2};
double NdataE[] = { 579.8, 202.8, 95.4};
double NW [] = {258150.0, 0.38, 14.8};
double NWE[] = { 502.8, 0.38, 3.1};
double NZ [] = { 19473.9, 37494.8, 181.4};
double NZE[] = { 61.7, 75.4, 5.2};
double Ntt [] = { 33156.3, 1637.8, 8214.0};
double NttE[] = { 32.9, 8.2, 18.3};
double Nother [] = { 20934.8, 606.9, 470.8};
double NotherE[] = { 494.4, 5.3, 10.7};
TH1F *W = new TH1F("W" ,"W" , 3, 0.5, 3.5);
TH1F *Z = new TH1F("Z" ,"Z" , 3, 0.5, 3.5);
TH1F *tt = new TH1F("tt" ,"tt" , 3, 0.5, 3.5);
TH1F *other = new TH1F("other","other", 3, 0.5, 3.5);
TH1F *data = new TH1F("data" ,"data" , 3, 0.5, 3.5);
TH1F *weightW = new TH1F("W_weight" , "W_weight" , 3, 0.5, 3.5);
TH1F *weightZ = new TH1F("Z_weight" , "Z_weight" , 3, 0.5, 3.5);
TH1F *weighttt = new TH1F("tt_weight", "tt_weight", 3, 0.5, 3.5);
for(int i=0; i<3; i++){
double Nw_prime = TMath::Power(NW[i]/NWE[i] , 2);
double NZ_prime = TMath::Power(NZ[i]/NZE[i] , 2);
double Ntt_prime = TMath::Power(Ntt[i]/NttE[i] , 2);
//double Nother_prime = TMath::Power(Nother[i]/NotherE[i], 2);
W ->SetBinContent(i+1, Nw_prime );
Z ->SetBinContent(i+1, NZ_prime );
tt->SetBinContent(i+1, Ntt_prime);
weightW -> SetBinContent(i+1, NW[i] /W ->GetBinContent(i+1));
weightZ -> SetBinContent(i+1, NZ[i] /Z ->GetBinContent(i+1));
weighttt-> SetBinContent(i+1, Ntt[i]/tt->GetBinContent(i+1));
// other -> SetBinContent(i+1, Nother[i] );
data -> SetBinContent(i+1, Ndata[i]);
}
W ->SetLineColor(kRed );
Z ->SetLineColor(kBlue );
tt->SetLineColor(kGreen);
for(int i=1; i<=3; i++){
// cout << "data: " << data->GetBinContent(i) << " W " << W->GetBinContent(i) << " Z " << Z->GetBinContent(i) << " tt " << tt->GetBinContent(i) << endl;
// cout << "data weight=1, W weight " << weightW->GetBinContent(i) << " Z weight: " << weightZ->GetBinContent(i) << " weight tt " << weighttt->GetBinContent(i) << endl;
}
TObjArray *mc= new TObjArray(4);
mc->Add(W);
mc->Add(Z);
mc->Add(tt);
// mc->Add(other);
TFractionFitter *fit = new TFractionFitter(data,mc);
//fit->GetFitter()->FixParameter(3);
fit->SetWeight(0,weightW);
fit->SetWeight(1,weightZ);
fit->SetWeight(2,weighttt);
//fit->Constrain(0,0,2);
//fit->Constrain(1,0,2);
//fit->Constrain(2,0,2);
fit->Fit();
double R[3];
for(int i=0; i<3; i++){
double x=0;
double xE=0;
fit->GetResult(i,x,xE);
double N=0;
if (i==0) N = NW[i] ;
if (i==1) N = NZ[i] ;
if (i==2) N = Ntt[i];
cout << "x " << x << endl;
cout << " initial fraction: " << Ndata[i]/N << endl;
R[i]=x*(Ndata[i]/N);
cout << "R: " << R[i] << " +/- " << (xE/x)*R[i] << endl;
}
}
