void fithist() {
//fit function ftotal to signal + background
histgen();
TFile *f = new TFile("background.root");
background = (TH1F*)f->Get("background"); //pointer used in ftotal
TH1F *result = (TH1F*)f->Get("result");
TF1 *ftot = new TF1("ftot",ftotal,0,10,4);
Double_t norm = result->GetMaximum();
ftot->SetParameters(0.5*norm,5,.2,norm);
ftot->SetParLimits(0,.3*norm,norm);
result->Fit("ftot","b");
}
void test_TF1_FitErr2(){
gStyle->SetOptFit(1111);
gStyle->SetOptStat(0);
histgen();
TFile *f = new TFile("background.root");
background = (TH1F*)f->Get("background"); //pointer used in ftotal
TH1F *result = (TH1F*)f->Get("result");
TF1 *ftot = new TF1("ftot",ftotal,0,10,5);
Double_t norm = result->GetMaximum();
// ftot->SetParameters(0.5*norm,5,.2,norm);
ftot->SetParameters(0.5*norm,6,.5,5,-0.5);
ftot->SetParLimits(0,.3*norm,norm);
// ftot->FixParameter(1,6);
// ftot->FixParameter(2,0.5);
ftot->SetParLimits(1,5.5,6.5);
ftot->SetParLimits(2,0.25,1);
// ftot->SetParLimits(4,-0.01,-50);
result->Fit("ftot","b");
result->Fit("ftot","b");
result->Fit("ftot","b");
result->Fit("ftot");
result->Fit("ftot");
result->Fit("ftot");
TFitResult fitResult=result->Fit("ftot");
double
TF1 *bgf = TF1("bgf","pol1",0,10);
}
