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FitAwmi.C File Reference
Tutorials » Spectrum tutorials

Detailed Description

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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 -9.76 34.9074 7
created -9.28 29.9207 6
created -8.8 24.9339 5
created -8.32 19.9471 4
created -7.84 49.8678 10
created -7.36 49.8678 10
created -6.88 29.9207 6
created -6.4 14.9603 3
created -5.92 49.8678 10
created -5.44 4.98678 1
created -4.96 24.9339 5
created -4.48 9.97356 2
created -4 44.881 9
created -3.52 19.9471 4
created -3.04 34.9074 7
created -2.56 24.9339 5
created -2.08 44.881 9
created -1.6 49.8678 10
created -1.12 44.881 9
created -0.64 39.8942 8
created -0.16 4.98678 1
created 0.32 24.9339 5
created 0.8 34.9074 7
created 1.28 14.9603 3
created 1.76 9.97356 2
created 2.24 44.881 9
created 2.72 24.9339 5
created 3.2 44.881 9
created 3.68 9.97356 2
created 4.16 24.9339 5
created 4.64 24.9339 5
created 5.12 44.881 9
created 5.6 44.881 9
created 6.08 44.881 9
created 6.56 24.9339 5
created 7.04 19.9471 4
created 7.52 9.97356 2
created 8 44.881 9
created 8.48 24.9339 5
created 8.96 34.9074 7
created 9.44 49.8678 10
the total number of created peaks = 41 with sigma = 0.08
the total number of found peaks = 41 with sigma = 0.0800011 (+-2.98589e-05)
fit chi^2 = 5.62937e-06
found -7.84 (+-0.000261263) 49.8678 (+-0.160501) 10.0001 (+-0.00106287)
found -7.36 (+-0.000261596) 49.8679 (+-0.160526) 10.0002 (+-0.00106303)
found -5.92 (+-0.000259435) 49.8673 (+-0.160369) 10 (+-0.00106199)
found -1.6 (+-0.000261873) 49.868 (+-0.160547) 10.0002 (+-0.00106317)
found 9.44 (+-0.000259186) 49.868 (+-0.160369) 10.0002 (+-0.00106199)
found -4 (+-0.000274197) 44.8807 (+-0.152185) 9.00006 (+-0.0010078)
found -2.08 (+-0.000275795) 44.8812 (+-0.152292) 9.00015 (+-0.0010085)
found -1.12 (+-0.000276261) 44.8813 (+-0.152324) 9.00018 (+-0.00100871)
found 2.24 (+-0.000274388) 44.8808 (+-0.152198) 9.00007 (+-0.00100788)
found 3.2 (+-0.000274388) 44.8808 (+-0.152198) 9.00007 (+-0.00100788)
found 5.12 (+-0.000275675) 44.8811 (+-0.152283) 9.00014 (+-0.00100845)
found 5.6 (+-0.00027627) 44.8813 (+-0.152324) 9.00018 (+-0.00100872)
found 6.08 (+-0.000275675) 44.8811 (+-0.152283) 9.00014 (+-0.00100845)
found 8 (+-0.000274388) 44.8808 (+-0.152198) 9.00007 (+-0.00100788)
found -0.640001 (+-0.00029145) 39.8942 (+-0.143522) 8.0001 (+-0.000950431)
found -9.76 (+-0.000312318) 34.9073 (+-0.134276) 7.00006 (+-0.000889197)
found -3.04 (+-0.000312214) 34.9074 (+-0.134281) 7.00009 (+-0.000889232)
found 0.8 (+-0.000311932) 34.9074 (+-0.134266) 7.00008 (+-0.000889136)
found 8.96 (+-0.00031334) 34.9078 (+-0.134343) 7.00015 (+-0.00088964)
found -9.28 (+-0.000338335) 29.9209 (+-0.124371) 6.00012 (+-0.000823608)
found -6.88 (+-0.000338282) 29.9209 (+-0.124371) 6.00013 (+-0.000823606)
found -8.8 (+-0.000370615) 24.9341 (+-0.113534) 5.0001 (+-0.000751845)
found -2.56 (+-0.000372184) 24.9344 (+-0.113597) 5.00016 (+-0.00075226)
found 2.72 (+-0.000372634) 24.9345 (+-0.113615) 5.00018 (+-0.000752382)
found 6.56 (+-0.000371315) 24.9342 (+-0.113563) 5.00013 (+-0.000752034)
found 8.48 (+-0.000372184) 24.9344 (+-0.113597) 5.00016 (+-0.00075226)
found -4.96 (+-0.000367672) 24.9337 (+-0.113425) 5.00003 (+-0.000751119)
found 0.320002 (+-0.00036936) 24.934 (+-0.11349) 5.00008 (+-0.000751553)
found 4.16 (+-0.000369481) 24.9339 (+-0.113492) 5.00007 (+-0.000751561)
found 4.64 (+-0.000371641) 24.9343 (+-0.113576) 5.00014 (+-0.000752118)
found -3.52 (+-0.000417042) 19.9477 (+-0.101635) 4.00016 (+-0.000673045)
found -8.32 (+-0.000416623) 19.9476 (+-0.101622) 4.00015 (+-0.000672958)
found 7.04 (+-0.000413761) 19.9472 (+-0.10153) 4.00007 (+-0.000672353)
found -6.4 (+-0.00048298) 14.961 (+-0.0880548) 3.00016 (+-0.000583115)
found 1.28 (+-0.000479692) 14.9606 (+-0.0879747) 3.00009 (+-0.000582584)
found 3.68 (+-0.000593393) 9.97414 (+-0.0719289) 2.00014 (+-0.000476326)
found -4.48 (+-0.000593393) 9.97414 (+-0.0719289) 2.00014 (+-0.000476326)
found 1.76 (+-0.00059182) 9.97404 (+-0.0719031) 2.00012 (+-0.000476155)
found 7.52 (+-0.000592672) 9.97409 (+-0.0719169) 2.00013 (+-0.000476247)
found -5.44001 (+-0.00084808) 4.98748 (+-0.0509423) 1.00015 (+-0.000337349)
found -0.160004 (+-0.000846495) 4.98738 (+-0.050927) 1.00013 (+-0.000337248)
#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;
}
d
#define d(i)
Definition RSha256.hxx:102
f
#define f(i)
Definition RSha256.hxx:104
h
#define h(i)
Definition RSha256.hxx:106
Bool_t
bool Bool_t
Definition RtypesCore.h:63
Int_t
int Int_t
Definition RtypesCore.h:45
kFALSE
constexpr Bool_t kFALSE
Definition RtypesCore.h:101
Double_t
double Double_t
Definition RtypesCore.h:59
kRed
@ kRed
Definition Rtypes.h:66
dest
Option_t Option_t TPoint TPoint const char GetTextMagnitude GetFillStyle GetLineColor GetLineWidth GetMarkerStyle GetTextAlign GetTextColor GetTextSize void char Point_t Rectangle_t dest
Definition TGWin32VirtualXProxy.cxx:164
x1
Option_t Option_t TPoint TPoint const char x1
Definition TGWin32VirtualXProxy.cxx:70
i
Int_t i
Definition TGraphAsymmErrors.cxx:1306
xmin
float xmin
Definition THbookFile.cxx:95
xmax
float xmax
Definition THbookFile.cxx:95
gROOT
#define gROOT
Definition TROOT.h:414
gRandom
R__EXTERN TRandom * gRandom
Definition TRandom.h:62
TAttMarker::SetMarkerColor
virtual void SetMarkerColor(Color_t mcolor=1)
Set the marker color.
Definition TAttMarker.h:38
TAttMarker::SetMarkerStyle
virtual void SetMarkerStyle(Style_t mstyle=1)
Set the marker style.
Definition TAttMarker.h:40
TAttMarker::SetMarkerSize
virtual void SetMarkerSize(Size_t msize=1)
Set the marker size.
Definition TAttMarker.h:45
TCanvas
The Canvas class.
Definition TCanvas.h:23
TCanvas::Clear
void Clear(Option_t *option="") override
Remove all primitives from the canvas.
Definition TCanvas.cxx:734
TF1
1-Dim function class
Definition TF1.h:233
TH1F
1-D histogram with a float per channel (see TH1 documentation)
Definition TH1.h:621
TPolyMarker
A PolyMarker is defined by an array on N points in a 2-D space.
Definition TPolyMarker.h:31
TSpectrumFit
Advanced 1-dimensional spectra fitting functions.
Definition TSpectrumFit.h:18
TSpectrumFit::GetChi
Double_t GetChi() const
Definition TSpectrumFit.h:121
TSpectrumFit::SetPeakParameters
void SetPeakParameters(Double_t sigma, Bool_t fixSigma, const Double_t *positionInit, const Bool_t *fixPosition, const Double_t *ampInit, const Bool_t *fixAmp)
This function sets the following fitting parameters of peaks:
Definition TSpectrumFit.cxx:2658
TSpectrumFit::GetAmplitudesErrors
Double_t * GetAmplitudesErrors() const
Definition TSpectrumFit.h:117
TSpectrumFit::FitAwmi
void FitAwmi(Double_t *source)
This function fits the source spectrum.
Definition TSpectrumFit.cxx:822
TSpectrumFit::GetAreasErrors
Double_t * GetAreasErrors() const
Definition TSpectrumFit.h:119
TSpectrumFit::GetSigma
void GetSigma(Double_t &sigma, Double_t &sigmaErr)
This function gets the sigma parameter and its error.
Definition TSpectrumFit.cxx:2727
TSpectrumFit::GetAreas
Double_t * GetAreas() const
Definition TSpectrumFit.h:118
TSpectrumFit::GetAmplitudes
Double_t * GetAmplitudes() const
Definition TSpectrumFit.h:116
TSpectrumFit::SetFitParameters
void SetFitParameters(Int_t xmin, Int_t xmax, Int_t numberIterations, Double_t alpha, Int_t statisticType, Int_t alphaOptim, Int_t power, Int_t fitTaylor)
This function sets the following fitting parameters:
Definition TSpectrumFit.cxx:2610
TSpectrumFit::GetPositionsErrors
Double_t * GetPositionsErrors() const
Definition TSpectrumFit.h:123
TSpectrumFit::GetPositions
Double_t * GetPositions() const
Definition TSpectrumFit.h:122
TSpectrum
Advanced Spectra Processing.
Definition TSpectrum.h:18
TSpectrum::SearchHighRes
Int_t SearchHighRes(Double_t *source, Double_t *destVector, Int_t ssize, Double_t sigma, Double_t threshold, bool backgroundRemove, Int_t deconIterations, bool markov, Int_t averWindow)
One-dimensional high-resolution peak search function.
Definition TSpectrum.cxx:2129
TSpectrum::GetPositionX
Double_t * GetPositionX() const
Definition TSpectrum.h:58
sigma
const Double_t sigma
Definition h1analysisProxy.h:11
TMath::Sqrt2
constexpr Double_t Sqrt2()
Definition TMath.h:86
TMath::Sqrt
Double_t Sqrt(Double_t x)
Returns the square root of x.
Definition TMath.h:662
TMath::TwoPi
constexpr Double_t TwoPi()
Definition TMath.h:44
Author

Definition in file FitAwmi.C.