SearchHR1.C File Reference

Detailed Description

Example to illustrate high resolution peak searching function (class TSpectrum).

 
void SearchHR1()
{
   Double_t fPositionX[100];
   Double_t fPositionY[100];
   Int_t fNPeaks = 0;
   Int_t i, nfound, bin;
   const Int_t nbins = 1024;
   Double_t xmin = 0;
   Double_t xmax = nbins;
   Double_t a;
   Double_t source[nbins], dest[nbins];
   gROOT->ForceStyle();
 
   TString dir = gROOT->GetTutorialDir();
   TString file = dir + "/legacy/spectrum/TSpectrum.root";
   TFile *f = new TFile(file.Data());
   TH1F *h = (TH1F *)f->Get("back2");
   h->SetTitle("High resolution peak searching, number of iterations = 3");
   h->GetXaxis()->SetRange(1, nbins);
   TH1F *d = new TH1F("d", "", nbins, xmin, xmax);
   h->Draw("L");
 
   for (i = 0; i < nbins; i++)
      source[i] = h->GetBinContent(i + 1);
 
   h->Draw("L");
 
   TSpectrum *s = new TSpectrum();
 
   nfound = s->SearchHighRes(source, dest, nbins, 8, 2, kTRUE, 3, kTRUE, 3);
   Double_t *xpeaks = s->GetPositionX();
   for (i = 0; i < nfound; i++) {
      a = xpeaks[i];
      bin = 1 + Int_t(a + 0.5);
      fPositionX[i] = h->GetBinCenter(bin);
      fPositionY[i] = h->GetBinContent(bin);
   }
 
   TPolyMarker *pm = (TPolyMarker *)h->GetListOfFunctions()->FindObject("TPolyMarker");
   if (pm) {
      h->GetListOfFunctions()->Remove(pm);
      delete pm;
   }
   pm = new TPolyMarker(nfound, fPositionX, fPositionY);
   h->GetListOfFunctions()->Add(pm);
   pm->SetMarkerStyle(23);
   pm->SetMarkerColor(kRed);
   pm->SetMarkerSize(1.3);
 
   for (i = 0; i < nbins; i++)
      d->SetBinContent(i + 1, dest[i]);
   d->SetLineColor(kRed);
   d->Draw("SAME");
 
   printf("Found %d candidate peaks\n", nfound);
   for (i = 0; i < nfound; i++)
      printf("posx= %f, posy= %f\n", fPositionX[i], fPositionY[i]);
}

Authors

Miroslav Morhac, Olivier Couet

Definition in file SearchHR1.C.