--- /dev/null
+void DrawSlice(Double_t p, Bool_t singlePiGauss){
+ //TVirtualFitter::Set
+ TFile *in = TFile::Open("HFEtask.root");
+ TList *qa = (TList *)in->Get("HFE_QA");
+
+ // Make Plots for TPC
+ TList *pidqa = (TList *)qa->FindObject("HFEpidQA");
+ AliHFEtpcPIDqa *tpcqa = (AliHFEtpcPIDqa *)pidqa->FindObject("TPCQA");
+ TH2 *hTPCsig = tpcqa->MakeSpectrumNSigma(AliHFEdetPIDqa::kBeforePID);
+
+ // define cut model
+ TF1 cutmodel("cutmodel", "[0] * TMath::Exp([1]*x) + [2]", 0, 20);
+ cutmodel.SetParameter(0, -2.75);
+ cutmodel.SetParameter(1, -0.8757);
+ cutmodel.SetParameter(2, -0.9);
+
+ Int_t nBinsP = 0;
+ Int_t pbin = hTPCsig->GetXaxis()->FindBin(p);
+ TH1 *hslice = hTPCsig->ProjectionY("hslice", pbin - nBinsP, pbin + nBinsP);
+
+ // Functions needed
+ TF1 *pi1 = new TF1("pi1", "[0] * TMath::Gaus(x, [1], [2]) + [3]*TMath::Gaus(x, [4], [5])", -20, 20),
+ *pi2 = new TF1("pi2", "[0] * TMath::Gaus(x, [1], [2]) + [3]*TMath::Gaus(x, [4], [5])", -20, 20),
+ *el1 = new TF1("el1", "[0] * TMath::Gaus(x, [1], [2])", -20, 20),
+ *el2 = new TF1("el1", "[0] * TMath::Gaus(x, [1], [2])", -20, 20),
+ *combined = new TF1("combined", "[0] * TMath::Gaus(x, [1], [2]) + [3]*TMath::Gaus(x, [4], [5]) +[6] * TMath::Gaus(x, [7], [8])" , -20, 20);
+
+ // Constraints
+ Double_t minele = 1e0;
+ Double_t maxele = 1e4;
+ Double_t minpi = 1e2;
+ Double_t maxpi = 1e5;
+ pi1->SetParLimits(0, minpi, maxpi); pi1->SetParLimits(3, minpi, maxpi);
+ pi1->SetParLimits(2, 0.4, 0.9); pi1->SetParLimits(5, 0.4, 0.9);
+ pi1->SetParLimits(1, -6.5,-3.5); pi1->SetParLimits(4, -6.5,-3.);
+ if(singlePiGauss){
+ pi1->FixParameter(3,0);
+ pi1->FixParameter(4,0);
+ pi1->FixParameter(5,0);
+ }
+ el1->SetParLimits(0, minele, maxele);
+ el1->SetParLimits(1, -0.4, 0.);
+ el1->SetParLimits(2, 0.9, 1.3);
+ el1->SetParameter(1, -0.1);
+
+ // test
+ //el1->FixParameter(1, -3.78551e-01);
+ hslice->Fit(pi1, "N", "", -8., -3.);
+ hslice->Fit(el1, "LN", "", -1.1, 5);
+
+ // Use single fits to constrain combined fit
+ combined->FixParameter(1, pi1->GetParameter(1));
+ combined->FixParameter(2, pi1->GetParameter(2));
+ combined->FixParameter(4, pi1->GetParameter(4));
+ combined->FixParameter(5, pi1->GetParameter(5));
+ combined->FixParameter(7, el1->GetParameter(1));
+ combined->FixParameter(8, el1->GetParameter(2));
+ if(singlePiGauss)
+ combined->FixParameter(3, 0);
+ else
+ combined->SetParLimits(3, minpi, maxpi);
+ combined->SetParLimits(0, minpi, maxpi);
+ combined->SetParLimits(6, minele, maxele);
+
+ hslice->Fit(combined, "", "N", -8., 3.);
+
+ for(Int_t ipar = 0; ipar < 6; ipar++) pi2->SetParameter(ipar, combined->GetParameter(ipar));
+ for(Int_t ipar = 0; ipar < 3; ipar++) el2->SetParameter(ipar, combined->GetParameter(ipar+6));
+
+ combined->SetLineColor(kBlack);
+ el2->SetLineColor(kGreen);
+ pi2->SetLineColor(kBlue);
+ combined->SetLineWidth(2);
+ el2->SetLineWidth(2);
+ pi2->SetLineWidth(2);
+ el2->SetLineStyle(2);
+ pi2->SetLineStyle(2);
+
+ hslice->SetStats(kFALSE);
+ hslice->SetTitle("TPC Signal");
+ hslice->GetXaxis()->SetTitle("TPC dE/dx - <dE/dx>|_{electrons} [#sigma]");
+
+ TCanvas *output = new TCanvas("output", "Slice output");
+ output->SetLogy();
+ output->cd();
+ hslice->Draw();
+ combined->Draw("same");
+ el2->Draw("same");
+ pi2->Draw("same");
+
+ TLegend *leg = new TLegend(0.5, 0.7, 0.89, 0.89);
+ leg->SetFillStyle(0);
+ leg->SetBorderSize(0);
+ leg->AddEntry(hslice, "Measurement", "l");
+ leg->AddEntry(combined, "Electrons + Pions", "l");
+ leg->AddEntry(el2, "Electrons", "l");
+ leg->AddEntry(pi2, "Pions", "l");
+ leg->Draw();
+
+ TPaveText *momentum = new TPaveText(0.6, 0.45, 0.8, 0.55, "NDC");
+ momentum->SetBorderSize(0);
+ momentum->SetFillStyle(0);
+ momentum->AddText(Form("p = %.2fGeV/c", p));
+ momentum->Draw();
+
+ // Draw also Selection Bands
+ TF1 *fBandPions = new TF1(*pi2), *fBandElectrons = new TF1(*el2);
+ fBandPions->SetRange(cutmodel.Eval(p), 5);
+ fBandElectrons->SetRange(cutmodel.Eval(p), 5);
+
+ fBandPions->SetFillColor(kBlue);
+ fBandPions->SetFillStyle(3004);
+ fBandElectrons->SetFillColor(kGreen);
+ fBandElectrons->SetFillStyle(3005);
+ fBandPions->SetLineWidth(0);
+ fBandElectrons->SetLineWidth(0);
+
+ fBandElectrons->Draw("same");
+ fBandPions->Draw("same");
+
+ // Now calculate the contamination
+ Double_t nPions = pi2->Integral(cutmodel.Eval(p), 5);
+ Double_t nCandidates = combined->Integral(cutmodel.Eval(p), 5);
+ Double_t contamination = nPions/nCandidates;
+ Double_t nCandidatesHisto = hslice->Integral(hslice->GetXaxis()->FindBin(cutmodel.Eval(p)), hslice->GetXaxis()->FindBin(5));
+ Double_t nPionsBefore = pi1->Integral(cutmodel.Eval(p), 5);
+ Double_t contaminationHisto = nPionsBefore/nCandidatesHisto;
+ printf("Contamination @ %.3fGeV/c: %f\n", p, contamination);
+ printf("Contamination @ %.3fGeV/c: %f (determined from double gauss and histogram)\n", p, contaminationHisto);
+
+ TPaveText *tcont = new TPaveText(0.45, 0.35, 0.9, 0.45, "NDC");
+ tcont->SetBorderSize(0);
+ tcont->SetFillStyle(0);
+ tcont->AddText(Form("contamination: %f", contamination));
+ tcont->Draw();
+
+ // Save Canvas
+ TString filename = Form("slice%d.root", ((Int_t)(100*p)));
+ if(singlePiGauss)
+ filename = Form("slice%dsingle.root", ((Int_t)(100*p)));
+
+ TFile *out = new TFile(filename.Data(), "RECREATE");
+ out->cd();
+ output->Write();
+ out->Close(); delete out;
+}