FitAwmi.C File Reference

Detailed Description

This macro fits the source spectrum using the AWMI algorithm from the "TSpectrumFit" class ("TSpectrum" class is used to find peaks).

To try this macro, in a ROOT (5 or 6) prompt, do:

root > .x FitAwmi.C

or:

root > .x FitAwmi.C++
root > FitAwmi(); // re-run with another random set of peaks

 
created -9.82 59.8413 9
created -9.46 46.5433 7
created -9.1 26.5962 4
created -8.74 33.2452 5
created -8.38 59.8413 9
created -8.02 53.1923 8
created -7.66 53.1923 8
created -7.3 59.8413 9
created -6.94 53.1923 8
created -6.58 26.5962 4
created -6.22 59.8413 9
created -5.86 6.64904 1
created -5.5 66.4904 10
created -5.14 26.5962 4
created -4.78 46.5433 7
created -4.42 46.5433 7
created -4.06 66.4904 10
created -3.7 46.5433 7
created -3.34 13.2981 2
created -2.98 13.2981 2
created -2.62 6.64904 1
created -2.26 13.2981 2
created -1.9 46.5433 7
created -1.54 66.4904 10
created -1.18 46.5433 7
created -0.82 46.5433 7
created -0.46 39.8942 6
created -0.1 66.4904 10
created 0.26 19.9471 3
created 0.62 53.1923 8
created 0.98 6.64904 1
created 1.34 39.8942 6
created 1.7 46.5433 7
created 2.06 6.64904 1
created 2.42 6.64904 1
created 2.78 46.5433 7
created 3.14 33.2452 5
created 3.5 6.64904 1
created 3.86 46.5433 7
created 4.22 6.64904 1
created 4.58 59.8413 9
created 4.94 6.64904 1
created 5.3 19.9471 3
created 5.66 46.5433 7
created 6.02 13.2981 2
created 6.38 39.8942 6
created 6.74 59.8413 9
created 7.1 39.8942 6
created 7.46 13.2981 2
created 7.82 19.9471 3
created 8.18 53.1923 8
created 8.54 13.2981 2
created 8.9 53.1923 8
created 9.26 59.8413 9
created 9.62 39.8942 6
the total number of created peaks = 55 with sigma = 0.06
the total number of found peaks = 55 with sigma = 0.0600004 (+-1.27481e-05)
fit chi^2 = 2.30779e-06
found -5.5 (+-0.000122762) 66.4901 (+-0.134815) 10 (+-0.000680034)
found -4.06 (+-0.000123586) 66.4905 (+-0.134919) 10.0001 (+-0.000680562)
found -1.54 (+-0.000123586) 66.4905 (+-0.134919) 10.0001 (+-0.000680562)
found -0.1 (+-0.000123201) 66.4903 (+-0.134869) 10.0001 (+-0.000680307)
found -7.3 (+-0.000130504) 59.8416 (+-0.128024) 9.00011 (+-0.000645782)
found 9.26 (+-0.000130365) 59.8416 (+-0.128007) 9.00009 (+-0.000645696)
found -9.82 (+-0.000130173) 59.8412 (+-0.127973) 9.00005 (+-0.000645525)
found -8.38 (+-0.000130284) 59.8415 (+-0.127998) 9.00009 (+-0.000645647)
found -6.22 (+-0.000129466) 59.8412 (+-0.127903) 9.00003 (+-0.000645172)
found 4.58 (+-0.000129052) 59.841 (+-0.127857) 9.00001 (+-0.00064494)
found 6.74 (+-0.000130227) 59.8415 (+-0.12799) 9.00008 (+-0.00064561)
found -8.02 (+-0.000138618) 53.1927 (+-0.120725) 8.00011 (+-0.00060896)
found -7.66 (+-0.000138618) 53.1927 (+-0.120725) 8.00011 (+-0.00060896)
found -6.94 (+-0.000138272) 53.1925 (+-0.120687) 8.00009 (+-0.000608772)
found 0.62 (+-0.00013728) 53.1921 (+-0.120584) 8.00003 (+-0.000608252)
found 8.18 (+-0.000137481) 53.1922 (+-0.120603) 8.00003 (+-0.000608349)
found 8.9 (+-0.000138006) 53.1924 (+-0.12066) 8.00007 (+-0.000608636)
found -9.46 (+-0.000147969) 46.5435 (+-0.112907) 7.00009 (+-0.000569527)
found -3.7 (+-0.000147738) 46.5435 (+-0.112887) 7.00008 (+-0.000569427)
found -1.18 (+-0.000148346) 46.5437 (+-0.112943) 7.00011 (+-0.000569709)
found -4.78 (+-0.000147811) 46.5434 (+-0.112891) 7.00007 (+-0.000569448)
found -4.42 (+-0.000148346) 46.5437 (+-0.112943) 7.00011 (+-0.000569709)
found -1.9 (+-0.000147738) 46.5435 (+-0.112887) 7.00008 (+-0.000569427)
found -0.82 (+-0.000148026) 46.5435 (+-0.112912) 7.00009 (+-0.00056955)
found 1.7 (+-0.000147195) 46.5432 (+-0.112837) 7.00005 (+-0.000569172)
found 2.78 (+-0.000147096) 46.5432 (+-0.112827) 7.00004 (+-0.000569124)
found 3.86 (+-0.000146465) 46.543 (+-0.112771) 7.00001 (+-0.000568838)
found 5.66 (+-0.000147078) 46.5432 (+-0.112823) 7.00003 (+-0.000569105)
found 7.1 (+-0.000159677) 39.8944 (+-0.104521) 6.00007 (+-0.000527228)
found 9.62 (+-0.000158697) 39.8946 (+-0.104459) 6.0001 (+-0.000526915)
found -0.46 (+-0.000160453) 39.8947 (+-0.104584) 6.00011 (+-0.000527543)
found 1.34 (+-0.000159235) 39.8943 (+-0.104487) 6.00005 (+-0.000527053)
found 6.38 (+-0.000159677) 39.8944 (+-0.104521) 6.00007 (+-0.000527228)
found -8.74 (+-0.000175566) 33.2455 (+-0.095458) 5.00009 (+-0.000481511)
found 3.14 (+-0.000174641) 33.2453 (+-0.095397) 5.00005 (+-0.000481202)
found -9.1 (+-0.00019662) 26.5965 (+-0.0853985) 4.00008 (+-0.000430768)
found -6.58 (+-0.000197323) 26.5967 (+-0.0854396) 4.00011 (+-0.000430975)
found -5.14 (+-0.000197303) 26.5967 (+-0.0854386) 4.00011 (+-0.00043097)
found 0.26 (+-0.000228729) 19.9478 (+-0.0740328) 3.00012 (+-0.000373437)
found 5.3 (+-0.00022632) 19.9473 (+-0.0739303) 3.00005 (+-0.00037292)
found 7.82 (+-0.000226979) 19.9474 (+-0.073957) 3.00007 (+-0.000373054)
found -3.34 (+-0.000278872) 13.2984 (+-0.0604113) 2.00006 (+-0.000304727)
found 6.02 (+-0.000280414) 13.2986 (+-0.0604561) 2.00009 (+-0.000304953)
found 7.46 (+-0.000279112) 13.2984 (+-0.0604172) 2.00006 (+-0.000304757)
found 8.54 (+-0.000281161) 13.2987 (+-0.0604793) 2.00011 (+-0.00030507)
found -2.98 (+-0.00027641) 13.2981 (+-0.0603398) 2.00002 (+-0.000304367)
found -2.26 (+-0.000278169) 13.2983 (+-0.0603926) 2.00005 (+-0.000304633)
found -5.86 (+-0.00040285) 6.64985 (+-0.0428507) 1.00013 (+-0.000216148)
found 0.979999 (+-0.000400788) 6.64962 (+-0.0428164) 1.00009 (+-0.000215975)
found 4.22 (+-0.000401657) 6.64971 (+-0.0428308) 1.00011 (+-0.000216048)
found 4.94 (+-0.000399301) 6.64953 (+-0.0427938) 1.00008 (+-0.000215861)
found 2.06 (+-0.000396281) 6.64936 (+-0.0427483) 1.00005 (+-0.000215632)
found 3.5 (+-0.000399829) 6.64953 (+-0.0428008) 1.00008 (+-0.000215896)
found 2.42 (+-0.000396281) 6.64936 (+-0.0427483) 1.00005 (+-0.000215632)
found -2.62 (+-0.000394399) 6.64917 (+-0.0427161) 1.00003 (+-0.000215469)

 
#include "TROOT.h"
#include "TMath.h"
#include "TRandom.h"
#include "TH1.h"
#include "TF1.h"
#include "TCanvas.h"
#include "TSpectrum.h"
#include "TSpectrumFit.h"
#include "TPolyMarker.h"
#include "TList.h"
 
#include <iostream>
 
TH1F *FitAwmi_Create_Spectrum(void)
{
   Int_t nbins = 1000;
   Double_t xmin = -10., xmax = 10.;
   delete gROOT->FindObject("h"); // prevent "memory leak"
   TH1F *h = new TH1F("h", "simulated spectrum", nbins, xmin, xmax);
   h->SetStats(kFALSE);
   TF1 f("f", "TMath::Gaus(x, [0], [1], 1)", xmin, xmax);
   // f.SetParNames("mean", "sigma");
   gRandom->SetSeed(0); // make it really random
   // create well separated peaks with exactly known means and areas
   // note: TSpectrumFit assumes that all peaks have the same sigma
   Double_t sigma = (xmax - xmin) / Double_t(nbins) * Int_t(gRandom->Uniform(2., 6.));
   Int_t npeaks = 0;
   while (xmax > (xmin + 6. * sigma)) {
      npeaks++;
      xmin += 3. * sigma; // "mean"
      f.SetParameters(xmin, sigma);
      Double_t area = 1. * Int_t(gRandom->Uniform(1., 11.));
      h->Add(&f, area, ""); // "" ... or ... "I"
      std::cout << "created " << xmin << " " << (area / sigma / TMath::Sqrt(TMath::TwoPi())) << " " << area
                << std::endl;
      xmin += 3. * sigma;
   }
   std::cout << "the total number of created peaks = " << npeaks << " with sigma = " << sigma << std::endl;
   return h;
}
 
void FitAwmi(void)
{
 
   TH1F *h = FitAwmi_Create_Spectrum();
 
   TCanvas *cFit = ((TCanvas *)(gROOT->GetListOfCanvases()->FindObject("cFit")));
   if (!cFit)
      cFit = new TCanvas("cFit", "cFit", 10, 10, 1000, 700);
   else
      cFit->Clear();
   h->Draw("L");
   Int_t i, nfound, bin;
   Int_t nbins = h->GetNbinsX();
 
   Double_t *source = new Double_t[nbins];
   Double_t *dest = new Double_t[nbins];
 
   for (i = 0; i < nbins; i++)
      source[i] = h->GetBinContent(i + 1);
   TSpectrum *s = new TSpectrum(); // note: default maxpositions = 100
   // searching for candidate peaks positions
   nfound = s->SearchHighRes(source, dest, nbins, 2., 2., kFALSE, 10000, kFALSE, 0);
   // filling in the initial estimates of the input parameters
   Bool_t *FixPos = new Bool_t[nfound];
   Bool_t *FixAmp = new Bool_t[nfound];
   for (i = 0; i < nfound; i++)
      FixAmp[i] = FixPos[i] = kFALSE;
 
   Double_t *Pos, *Amp = new Double_t[nfound]; // ROOT 6
 
   Pos = s->GetPositionX(); // 0 ... (nbins - 1)
   for (i = 0; i < nfound; i++) {
      bin = 1 + Int_t(Pos[i] + 0.5); // the "nearest" bin
      Amp[i] = h->GetBinContent(bin);
   }
   TSpectrumFit *pfit = new TSpectrumFit(nfound);
   pfit->SetFitParameters(0, (nbins - 1), 1000, 0.1, pfit->kFitOptimChiCounts, pfit->kFitAlphaHalving, pfit->kFitPower2,
                          pfit->kFitTaylorOrderFirst);
   pfit->SetPeakParameters(2., kFALSE, Pos, FixPos, Amp, FixAmp);
   // pfit->SetBackgroundParameters(source[0], kFALSE, 0., kFALSE, 0., kFALSE);
   pfit->FitAwmi(source);
   Double_t *Positions = pfit->GetPositions();
   Double_t *PositionsErrors = pfit->GetPositionsErrors();
   Double_t *Amplitudes = pfit->GetAmplitudes();
   Double_t *AmplitudesErrors = pfit->GetAmplitudesErrors();
   Double_t *Areas = pfit->GetAreas();
   Double_t *AreasErrors = pfit->GetAreasErrors();
   delete gROOT->FindObject("d"); // prevent "memory leak"
   TH1F *d = new TH1F(*h);
   d->SetNameTitle("d", "");
   d->Reset("M");
   for (i = 0; i < nbins; i++)
      d->SetBinContent(i + 1, source[i]);
   Double_t x1 = d->GetBinCenter(1), dx = d->GetBinWidth(1);
   Double_t sigma, sigmaErr;
   pfit->GetSigma(sigma, sigmaErr);
 
   // current TSpectrumFit needs a sqrt(2) correction factor for sigma
   sigma /= TMath::Sqrt2();
   sigmaErr /= TMath::Sqrt2();
   // convert "bin numbers" into "x-axis values"
   sigma *= dx;
   sigmaErr *= dx;
 
   std::cout << "the total number of found peaks = " << nfound << " with sigma = " << sigma << " (+-" << sigmaErr << ")"
             << std::endl;
   std::cout << "fit chi^2 = " << pfit->GetChi() << std::endl;
   for (i = 0; i < nfound; i++) {
      bin = 1 + Int_t(Positions[i] + 0.5); // the "nearest" bin
      Pos[i] = d->GetBinCenter(bin);
      Amp[i] = d->GetBinContent(bin);
 
      // convert "bin numbers" into "x-axis values"
      Positions[i] = x1 + Positions[i] * dx;
      PositionsErrors[i] *= dx;
      Areas[i] *= dx;
      AreasErrors[i] *= dx;
 
      std::cout << "found " << Positions[i] << " (+-" << PositionsErrors[i] << ") " << Amplitudes[i] << " (+-"
                << AmplitudesErrors[i] << ") " << Areas[i] << " (+-" << AreasErrors[i] << ")" << std::endl;
   }
   d->SetLineColor(kRed);
   d->SetLineWidth(1);
   d->Draw("SAME L");
   TPolyMarker *pm = ((TPolyMarker *)(h->GetListOfFunctions()->FindObject("TPolyMarker")));
   if (pm) {
      h->GetListOfFunctions()->Remove(pm);
      delete pm;
   }
   pm = new TPolyMarker(nfound, Pos, Amp);
   h->GetListOfFunctions()->Add(pm);
   pm->SetMarkerStyle(23);
   pm->SetMarkerColor(kRed);
   pm->SetMarkerSize(1);
   // cleanup
   delete pfit;
   delete[] Amp;
   delete[] FixAmp;
   delete[] FixPos;
   delete s;
   delete[] dest;
   delete[] source;
   return;
}

Author

Definition in file FitAwmi.C.