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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 14.9603 3
created -9.28 4.98678 1
created -8.8 44.881 9
created -8.32 14.9603 3
created -7.84 9.97356 2
created -7.36 24.9339 5
created -6.88 29.9207 6
created -6.4 29.9207 6
created -5.92 39.8942 8
created -5.44 14.9603 3
created -4.96 24.9339 5
created -4.48 44.881 9
created -4 34.9074 7
created -3.52 49.8678 10
created -3.04 29.9207 6
created -2.56 34.9074 7
created -2.08 4.98678 1
created -1.6 19.9471 4
created -1.12 9.97356 2
created -0.64 44.881 9
created -0.16 4.98678 1
created 0.32 14.9603 3
created 0.8 34.9074 7
created 1.28 19.9471 4
created 1.76 19.9471 4
created 2.24 39.8942 8
created 2.72 24.9339 5
created 3.2 9.97356 2
created 3.68 4.98678 1
created 4.16 14.9603 3
created 4.64 39.8942 8
created 5.12 14.9603 3
created 5.6 49.8678 10
created 6.08 9.97356 2
created 6.56 34.9074 7
created 7.04 44.881 9
created 7.52 39.8942 8
created 8 14.9603 3
created 8.48 49.8678 10
created 8.96 29.9207 6
created 9.44 24.9339 5
the total number of created peaks = 41 with sigma = 0.08
the total number of found peaks = 41 with sigma = 0.0800011 (+-2.30047e-05)
fit chi^2 = 2.85266e-06
found -3.52 (+-0.000185967) 49.8678 (+-0.114252) 10.0001 (+-0.000756599)
found 5.6 (+-0.000184927) 49.8674 (+-0.114177) 10 (+-0.0007561)
found 8.48 (+-0.000185486) 49.8676 (+-0.114217) 10.0001 (+-0.000756366)
found -8.8 (+-0.00019476) 44.8806 (+-0.108308) 9.00004 (+-0.000717233)
found -4.48 (+-0.000196051) 44.881 (+-0.108391) 9.00012 (+-0.000717785)
found -0.64 (+-0.000194565) 44.8805 (+-0.108295) 9.00003 (+-0.000717151)
found 7.04 (+-0.000196382) 44.8812 (+-0.108414) 9.00015 (+-0.000717935)
found -5.92 (+-0.000207667) 39.8941 (+-0.102176) 8.00009 (+-0.000676626)
found 2.24 (+-0.000207712) 39.8941 (+-0.102178) 8.00009 (+-0.000676641)
found 4.64 (+-0.000207204) 39.894 (+-0.102148) 8.00006 (+-0.000676444)
found 7.52 (+-0.000207998) 39.8943 (+-0.102197) 8.00012 (+-0.000676764)
found -4 (+-0.000223583) 34.9079 (+-0.0956619) 7.00019 (+-0.000633491)
found -2.56 (+-0.000221611) 34.9073 (+-0.0955585) 7.00007 (+-0.000632805)
found 0.8 (+-0.000221882) 34.9073 (+-0.0955699) 7.00007 (+-0.000632881)
found 6.56 (+-0.000222324) 34.9075 (+-0.0955953) 7.00011 (+-0.00063305)
found -6.4 (+-0.000241162) 29.921 (+-0.0885498) 6.00014 (+-0.000586393)
found -3.04 (+-0.000241571) 29.9211 (+-0.0885695) 6.00017 (+-0.000586523)
found 8.96 (+-0.00024124) 29.921 (+-0.088554) 6.00015 (+-0.000586421)
found -6.88 (+-0.000240693) 29.9208 (+-0.0885275) 6.00011 (+-0.000586245)
found 2.72 (+-0.000263563) 24.9341 (+-0.0808122) 5.0001 (+-0.000535153)
found 9.44 (+-0.000261473) 24.9341 (+-0.0807454) 5.00011 (+-0.000534711)
found -7.36 (+-0.00026322) 24.934 (+-0.0807981) 5.00008 (+-0.00053506)
found -4.96 (+-0.000264052) 24.9342 (+-0.0808307) 5.00012 (+-0.000535276)
found 1.28 (+-0.000295742) 19.9474 (+-0.072313) 4.00011 (+-0.00047887)
found -1.6 (+-0.000292972) 19.947 (+-0.0722282) 4.00003 (+-0.000478309)
found 1.76 (+-0.000295941) 19.9475 (+-0.0723197) 4.00012 (+-0.000478914)
found -8.32 (+-0.000341959) 14.9607 (+-0.0626383) 3.00011 (+-0.000414802)
found -5.44 (+-0.000343044) 14.9608 (+-0.0626631) 3.00013 (+-0.000414966)
found 5.12 (+-0.000344358) 14.9611 (+-0.0626964) 3.00018 (+-0.000415187)
found 8 (+-0.000344357) 14.9611 (+-0.0626964) 3.00018 (+-0.000415187)
found -9.76 (+-0.000338572) 14.9602 (+-0.0625522) 3.00001 (+-0.000414232)
found 0.320003 (+-0.000340735) 14.9605 (+-0.0626097) 3.00008 (+-0.000414612)
found 4.16 (+-0.000340986) 14.9606 (+-0.0626162) 3.00009 (+-0.000414656)
found 6.08 (+-0.00042357) 9.97429 (+-0.0512234) 2.00017 (+-0.000339211)
found -7.84 (+-0.000419775) 9.97383 (+-0.0511581) 2.00008 (+-0.000338778)
found -1.12 (+-0.0004219) 9.97409 (+-0.0511948) 2.00013 (+-0.000339021)
found 3.2 (+-0.000417972) 9.97373 (+-0.0511304) 2.00006 (+-0.000338595)
found -0.160008 (+-0.000601151) 4.98733 (+-0.036241) 1.00012 (+-0.000239994)
found -9.27999 (+-0.000601151) 4.98733 (+-0.036241) 1.00012 (+-0.000239994)
found -2.08 (+-0.000601028) 4.98727 (+-0.0362388) 1.00011 (+-0.00023998)
found 3.68 (+-0.000595125) 4.98697 (+-0.0361866) 1.00005 (+-0.000239634)
#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.